Sound queue

@BrettASwift 

Some cleanup of the sound driver, fixed a different bug, but most relevant to you: made it so that
stopAllSoundInstances also clears out the sound queues (which should help with the problems
you're seeing when resetting the game).
Nifty!  Basically the same thing that I routinely do in C++ - I didn't realize you could do that in JS.

Will make this change, and then merge.