Slider Has No Way To Dynamically Add Handles

I've looked very hard through both the docs and the code, and as far as I can see there is no way to dynamically add a handle to a slider after it has been initialized. You can change the values (either by changing the values option or through the values() method), but if you add any values to the slider it won't reflect that with a corresponding handle.

The reason for this (again, as best as I can tell) is because all of the creation/event hooking-up of the handles occurs in the _init method of the slider (and therefore the only way to "add handles" currently is to destroy/recreate the slider). What would be much nicer (IMHO) is if this creation/event hooking-up was refactored in to a separate method, which could then be called both by _init and by some sort of new addHandle() method.