CLEANING DEVICES CONVERTIBLE BETWEEN FLOOR AND WALL TREATMENT CONFIGURATIONS CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of both U.S. application Ser. No. 10/386,009 filed on March 10, 2003 and U.S. application Ser. No. 10/385,982 filed on March 10, 2003. STATEMENT OF FEDERALLY SPONSORED RESEARCH/DEVELOPMENT [0002] Not applicable. FIELD OF THE INVENTION [0003] The present invention relates to cleaning devices that dispense cleaning agents such as floor, tile or window cleaning compositions. More particularly it provides devices that can be converted between an elongated configuration (such as would be used for floor mopping) and at least one shortened, lighter weight configuration (such as might be used for cleaning windows, walls and other surfaces). BACKGROUND OF THE INVENTION [0004] Cleaning devices have been developed that dispense a cleaning chemical onto the surface being cleaned. Some such devices supply the chemical through a gravity feed mechanism. However, gravity fed devices are not well suited for cleaning vertical surfaces such as windows or bathroom walls. [0005] Other such devices rely on an electrical pump to pump the liquid to a spray system. See e^g. U.S. patent application publication 2001/0046407. Such electrical pumping systems increase the weight of the device, making it awkward for use on a vertical surface, increase its cost, and require recharging or replacement of batteries. [0006] Other devices dispense cleaning chemicals in the form of aerosol sprays. These devices use an aerosol canister containing the cleaning chemical mixed with a gas propellant. The canister is mounted to a canister holder, which in turn is mounted on a pole or the like between a cleaning head on the device and a handle. The handle is typically long enough so that the cleaning head can be extended up to reach high ceilings or out to reach underneath furniture. Some of these devices provide remote actuation via trigger located near the remote handle. Examples of prior art aerosol cleaning systems of this general type are disclosed in U.S. Pat. Nos. 3,679,319; 3,794,217; 4,789,084; 4,886,191; 5,099,539 and 5,779,155. [0007] The Grab-it Go Mop of S.C. Johnson, Inc. is another example of a remotely triggerable aerosol spray cleaning device. It has a handle, an extension pole, a canister holder, and a cleaning head. However, the apparatus is designed so that once it is assembled for the first time the handle will be essentially permanently attached to the part that it is connected to (normally an extension pole), and the extension pole will be essentially permanently attached to the canister holder. This helps insure proper transmission of trigger movement to the actuator for the canister. [0008] While such an aerosol system does have significant advantages, the existing systems are not well suited for arraying the aerosol outlet at different distances from the handle for different cleaning applications. Thus, a device of this type optimized from the standpoint of weight and length for floor cleaning is not optimal for cleaning closer surfaces such as windows. [0009] Vacuum cleaners are used for cleaning floors and other surfaces. They are often provided with multiple different cleaning heads and one or more extension wands that can be positioned between the main hose and the cleaning head (depending on the cleaning application of interest). The wands can easily be assembled or disassembled from the other parts of the device. However, vacuum cleaners do not dispense an aerosol spray, and thus do not require the triggering mechanisms needed to remotely actuate such a spray. In particular, they do not solve the problem of how to pass triggering mechanisms through extension wands that may only optionally be present. [0010] U.S. patent 3,713,744 disclosed a dispenser system in which the cleaning head was capable of adjustment so as to render the device somewhat more suitable for cleaning walls or floors (alternatively). While this was of some value with respect to the lower portions of walls, it still did not provide optimal flexibility for reconfiguring the device, particularly with respect to the length of the assembly. [0011] Hence, a need still exists for improved dispenser systems that permit the length of the device to be readily modified, while still retaining remote triggering capability. SUMMARY OF THE INVENTION [0012] In one aspect the invention provides a cleaning apparatus having a handle linked to a first trigger; a canister holder having a section for mounting an aerosol can, a grip section, and a second trigger; an extension pole removably linkable to the canister holder adjacent one end of the extension pole and to the handle adjacent an opposite end of the extension pole; and a cleaning head linked to the canister holder. The apparatus is suitable to be assembled in a first alternative configuration where the extension wand is so linked to the handle and canister holder and movement of the first trigger can move the actuator, and then the apparatus can readily be reconfigured into an alternative configuration where neither the extension wand, nor handle are linked to the canister holder, but movement of the second trigger can still move the actuator. [0013] By "readily" throughout this application we mean that the parts need not be broken or require the application of tools to cause the reconfiguration, and that further within less than ten minutes (preferably less than a minute, even more preferably within less than thirty seconds) the parts can be reconfigured by an average adult consumer who has previously been instructed as to the means of reassembly. [0014] In a preferred form of this embodiment the apparatus is also such that the apparatus can be readily reconfigured from the alternative configuration into a third configuration where the handle is linked to the canister holder and the extension wand is not linked to the canister holder or handle, where movement of the first trigger can move the actuator. [0015] In another aspect the invention provides a cleaning apparatus that has a handle linked to a trigger, a canister holder having an actuator capable of actuating an aerosol can (if an aerosol can is mounted to the canister holder), an extension pole removably linkable to the canister holder adjacent one end of the extension pole and to the handle adjacent an opposite end of the extension pole, and a cleaning head linked to the canister holder. The apparatus can be assembled in a first configuration where the extension wand is so linked to the handle and canister holder and movement of the trigger can move the actuator. The apparatus can then be readily reconfigured in an alternative configuration where the extension wand is not linked to either the handle or canister holder (it is left out of the device), but the handle is linked to the canister holder and movement of the trigger can still move the actuator. [0016] In preferred forms the handle (and also the lower end of the extension wand) are formed with a first type of quick disconnect coupling element. An upper portion of the extension wand and an upper portion of the canister holder are formed with a second type of quick disconnect coupling element. By "quick" we mean that within less than one minute (preferably less than ten seconds) the parts at a joint can be disconnected by an average adult consumer who has previously been instructed as to the means cf disassembly. [0017] The first type of quick disconnect coupling element can be a male member, and the second type of quick disconnect coupling element can be a female member with a radially/transversely releasable latch. Both the first type and second type of quick disconnect coupling elements can have an axial bore which forms part of a passageway for receiving a sliding member coupled to the trigger and actuator. [0018] In another form of the invention the extension wand can have an axial socket, and at least one of the canister holder or handle can have a stem sized to fit into the socket. The extension wand can be releasably retained in the socket by a spring biased latch where the latch has a ramped surface engagable with a catch surface on the stem and a push button suitable for moving the latch in opposition to the spring. The latch can surround a periphery of the stem when the stem is positioned in the socket. [0019] In yet another aspect of the invention there can be an aerosol can positioned on the canister housing in a fashion where the actuator can be moved by the trigger to cause a dispensing of a chemical in the aerosol can. [0020] The preferred chemical is a cleaning chemical suitable for floors, tiles or windows. An example of such chemical would be a Windex aerosol spray sold by S.C. Johnson & Son, Inc. However, the nature of the chemical is not critical, and even could be just water. [0021] Yet another attribute of the invention is to provide a latching apparatus for releasably linking two pole segments together, regardless of the function the apparatus. This apparatus can comprise a first pole having a male stem with a radial catch surface, and a second pole having a female socket suitable to receive the male stem in telescoping fashion. The second pole can also have a radial opening adjacent the socket for receiving a transversely movable latch. The latch is spring biased in an outward direction, and is in the form of a slab having a central through bore suitable to receive the stem. [0022] The latch is suitable to catch on the radial catch surface when the latch is in one position. It is also suitable to permit the stem to pass along the central through bore when the latch is in a second position. [0023] The present invention thus provides improved cleaning devices that are quickly and easily adjustable in length (and to some extend weight) while retaining the ability of at least one remote trigger to operate the spray canister. The system is designed to be used with a cleaning head system that can also be optimized for the intended application. [0024] These and other advantages of the invention will be apparent from the detailed description which follows and the drawings. It should be understood that the following merely provides preferred embodiments of the invention. The claims should be looked to in order to understand the full scope of the invention . BRIEF DESCRIPTION OF THE DRAWINGS [0025] RG. 1 is a perspective view of a cleaning device according to the present invention, shown in a floor mop configuration; [0026] FIG. 2 is a side view of the device without the upper handle or extension wand, as might typically be used for vertical wall cleaning; [0027] FIG. 3 is an exploded perspective view of the cleaning device of RG. 1; [0028] RG. 4 is a exploded perspective view of a third form of the cleaning device, with the upper handle included, but with the extension wand excluded; [0029] RG. 5 is an enlarged partial exploded perspective view of a quick disconnect assembly structure between the handle and the canister holder; [0030] FIG. 6 is a partial exploded perspective view of the end of the canister holder which is part of the quick disconnect assembly; [0031] FIG. 7 is a more assembled perspective view thereof, albeit isolated from other parts of the canister holder; [0032] FIG. 8 is a partial cross-sectional view taken along line 8-8 of FIG. 1; [0033] FIG. 9 is a sectional view similar to FIG. 8 albeit showing the position of a sliding member of an actuation assembly when a spray trigger is activated; and [0034] FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 1 showing the triggering mechanism of the handle, and how it can alternatively actuate an actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0035] The preferred form of the present invention provides an assembly capable of being configured in a long form (with upper handle, extension wand, canister holder, long aerosol can, and cleaning head), a short form (with neither upper handle or extension wand, but with canister holder, short aerosol can, and cleaning head), or an intermediate form (with upper handle, no extension wand, canister holder, short or long aerosol can, and cleaning head). The long form would be best suited for mopping floors. The short form would be best suited for cleaning counter tops and/or windows. The intermediate form would be best suited for cleaning surfaces of vertical walls that are near the ceiling. [0036] In all cases, a trigger is provided to remotely activate the aerosol can. In some cases the trigger is on the handle. In others it is on the canister holder. It can also be on both. A primary benefit of the device is to permit the remote operation of an aerosol can at varying lengths away from the triggering handle, with the consumer being able to make quick adjustments depending on the particular cleaning application of interest. [0037] While the entire cleaning device will be described generally here, certain aspects of the device are more specifically described in co- pending U.S. applications Ser. Nos. 10/385,982 and 10/386,009, both filed on March 10, 2003, both of which are hereby incorporated by reference as though fully set forth herein. [0038] With reference to FIGS. 1 and 3, a cleaning device 10 includes as major components a remote handle assembly 12, an extension wand 14, a canister holder 16 having its own handle assembly 18 and also an adjustable can retainer assembly 20. The retainer assembly is suitable to alternatively hold an aerosol canister 22A or 22B. The canister contains a selected cleaning chemical. The assembly also has a cleaning head 24. [0039] The canister 22 is aligned and mounted to the support housing 16 by a "ski-boot" type connection having a toe stop 26, a T-rail (not shown) and a heel assembly 28 slidable along the rail. A locking tab (not shown) formed in the T-rail clicks into one of two receivers at two preset adjustment locations to alternatively hold full-size (FIG. 1-22A) or compact (FIG. 2-22B) canister. [0040] The heel assembly 28 has a spring biased latch (not shown) that engages an inside surface of a rim 30 at the bottom of the canister 22A/22B. The latch is operated by a thumb operated release lever 32, which when depressed clears the latch from the canister 22. Releasing the release lever 32 resets the latch so that the canister can be removed and another canister can be snapped in place. This aspect of the device is described in significantly greater detail in U.S. application Ser. No. 10/386,009 incorporated by reference above. [0041] One end of the support housing 16 connects to the cleaning head 24 by a quick disconnect coupler 34 mounted to a pivot mount 36 formed as an integral part of a backing plate 38 supporting a compressible pad 40. The pad 40 can be a substrate for mounting a cleaning cloth or dusting sheet, or it may be (or mount) a sponge or scrubber pad. The plate 38 and pad 40 could be replaced by a bristled brush head, wiper blade or any other suitable cleaning implement desired. [0042] The cleaning head coupler 34 allows for plug in type quick connection and disconnection of the cleaning head 24 to the canister support housing 16 and permits it to swivel about a swivel axis 42 and independently pivot about a pivot axis 44 lying in a plane perpendicular to that of the swivel axis 42. The cleaning head coupler 34 includes a swivel lockout feature having slidable locking member 46 that engages and prevents rotation of a swivel part 48 of the coupler 34. This aspect of the device is described in significantly more detail in U.S. application Ser. No. 10/385,982 incorporated by reference above. [0043] The remote handle assembly 12 is connectable to the end of the support housing 16 opposite the cleaning head 24 by the extension wand 14. The grip assembly 12 includes a hollow (two-piece) plastic pistol grip housing defining a handle 50 and a pivotally mounted trigger 52 operable by an index finger when gripping the handle 50. A hollow shaft extension 54 has a stem end 56 which plugs into a quick connect coupler 58 at one end of the extension wand 14. Similarly, an opposite, stem end 60 of the extension wand 14 plugs into another quick connect coupler 62 at the end of the support housing 16. [0044] The stem ends 56 and 60 are preferably separate plastic pieces fit into the ends of the shaft extension 54 and the extension wand 14. The stem ends 56 and 60 are identical as are the couplers 58 and 62. Thus, if desired, the extension wand 14 can be removed from the assembly so that the remote grip assembly 12 can be directly connected to the canister support housing 16 to create an intermediate length assembly (see FIG. 4). [0045] As shown in FIG. 2, the remote grip assembly 12 and the extension wand 14 can be completely removed from the assembly, with the device then being operated by a separate trigger 64 and held by a handle section 66 of the support housing 16. The trigger can be reached once the shorter canister 22B replaces the longer canister 22A. Also note that, as shown in FIG. 1, the longer canister 22A serves to block the trigger 64 such that when the device is stored as an assembled mop, accidental discharge of cleaner by items banging against the trigger 64 in a crowded closet is inhibited. [0046] As noted above, FIG. 1 shows the cleaning device 10 of the present invention fully assembled in a mop-like configuration for cleaning floors or ceilings. FIG. 2 shows the cleaning device 10 as configured for window cleaning and cleaning other close-up vertical surfaces such as bathroom tiles. FIG. 4 shows how the device could be used when cleaning near the top of walls. [0047] Apart from the flexibility of reconfiguration, another important aspect of the invention is the quick disconnect coupling system. There is, as shown in FIGS. 5-7, a male element 56 on the handle, a male element 60 on the extension wand, a female element 58 on the extension wand, and a female element 62 on the canister housing. Of course, the positioning of the male and female elements could be reversed. [0048] In an especially preferred form of the invention, the male elements 56 and 60 are identical to each other, and the female elements 58 and 62 are identical to each other. Thus, the element 56 can be directly used with the element 62 when the wand 14 is deleted from the assembly. When the wand is used, the element 56 can fit in the element 58 while the element 60 is used with the element 62. [0049] Coupler 62 includes an open-ended socket insert 70 which fits into an open end of the container support housing 16. The socket insert 70 defines a generally cylindrical passageway 72 between the extension wand and/or handle and the actuator extending from toe stop 26. As best seen in FIG. 6, the socket insert 70 has a transverse/radial slot 74 sized to fit a latch ring 76. The latch ring 76 is generally ring-shaped with flat sides and defines a unitary ramp 78 and push button 80. [0050] The latch ring 76 can slide within the slot 74 and is biased against such movement by a spring 82 mounted on a boss 84 underneath the push button 80. The latch ring 76 is sized to fit around the periphery of the stem end 56 when fully inserted into the coupler 62. As the stem end 56 is inserted into the coupler 62 the ramp 78 cams the latch ring 76 to compress the spring 82 until the ramp 78 fits into a recess 86 in the stem end 56 and engages a catch surface 88 (see FIG. 8). This arrangement allows the components to be quickly snapped together and also resists axial separation of the stem end 56 from the coupler 62 until the push button 82 is depressed and the extension wand 14 is pulled from the support housing 16. The socket insert 70 and the latch ring 76 are held in the support housing 16 by a retainer collar 90 that snaps onto tabs 92 at the end of the support housings 16. [0051] Referring now to HGS. 3 and 8-10, internal to the handle assembly 12, extension wand 14 and the support housing 16 is a movable actuator assembly linking triggers 52 and 64 to the valve of the canister 22 for spraying cleaner via the actuator associated with toe stop 26. The actuator assembly includes slidable core members, such as members 94 and 96, at least in each of the handle assembly 12, extension wand 14 and canister support housing 16. These members slide in response to movement of either of the triggers 52 and 64 and in turn pivot an actuator lever which protrudes though an opening in the toe stop 26 to operate the valve of the canister 22. [0052] Assemblies for remotely actuating an actuator with a remote handle trigger are described in U.S. Serial No. 10/384,877, filed on March 7, 2003 and U.S. Serial No. 09/951,632, filed on September 14, 2001, which are hereby incorporated by reference. [0053] Referring to FIGS. 1 and 8-10, the grip assembly 12, the extension wand 14 and the main body 16 housing have sliding core members, such as 94 and 96. The sliding members in the grip assembly 12 and the wand extension 14 are sized to extend through passageways, such as passageway 98, to the tips of the respective stem ends 56 and 60 such that when the associated trigger 52 or 64 is depressed they protrude from the stem ends 56 and 60 in contact with enlarged plunger ends, such as plunger end 100, of the adjacent sliding member in the mating part (as shown in FIG. 9). The large plunger ends help ensure transfer of motion between adjacent sliding members in the event they become slightly axially misaligned during operation. When trigger 52 is depressed it slides the sliding members in the remote grip assembly 12 downwardly which abut sliding members 94 and 96 in the respective extension wand 14 and main body 16, which will contact a trip leg 120 of trigger 64 in turn abutting another sliding member 122 in the main body 16. This in turn pivots an actuator lever 124, a working end of which moves components of a canister valve 126. [0054] In particular, the actuator lever 124 contacts (when either trigger 52 or 64 is depressed) a free end 126 of a lever arm 128 hinged at the opposite end to a cylindrical wall 130 of an overcap 110 mounted to the canister 22. The lever arm 128 moves a hollow valve stem 132 into abutment with the internal components of the canister valve 126 to dispense the cleaner. Although not shown, the lever arm 128 has a nozzle adapted to provide a fan-shaped spray at a predetermined angle as measured from the top of the overcap 66. [0055] A user generally utilizes the cleaning device like any conventional poled or hand-held cleaning aerosol device. When the user desires to spray cleaner onto the surface being cleaned, the user simply squeezes either trigger 52 or 64, which pivots a hinged part of the over cap 110 on the canister 22 which in turn moves the actuator 124 to open the canister valve and spray out cleaner near the cleaning head. When the trigger 52 or 64 is released, springs (not shown) bias the actuator assembly to its original, non-activated position (shown in FIG. 10), which allows the canister valve to close and stop spraying. [0056] The present invention thus provides an improved cleaning device that is quickly and easily adjustable in length and remotely triggerable. The quick disconnect coupler allows for movement of sliding inner core members to couple the remote trigger to the canister, while at the same time providing a simple plug in connection of the wand or the grip assembly to the canister support or between two or more segments of a longer extension wand assembly. The mating parts simply snap together by virtue of the spring biased latch and can be disassembled by simply depressing a button on the latch and separating the parts, [0057] It should be appreciated that merely preferred embodiments of the invention have been described above. However, many modifications and variations to this preferred embodiment will be apparent to those skilled in the art, which will be within the spirit and scope of the invention, and as such the invention should not be limited to the described embodiment. Accordingly, to ascertain the full scope of the invention, the following claims should be referenced. INDUSTRIAL APPLICABILITY [0058] The invention provides improved remotely triggerable cleaning devices that can be rapidly reconfigured to modify length or weight.