Sound Groups and Duck and Cut

Adds support for ducking and cutting. Fixes a bug that would prevent soundQueues from accepting more than 2 instances at times. @kadst43 
Why are we ducking the stuff in the queue?  I thought the queue was a list of sounds that aren't playing yet?  I would think you'd go through all of the sounds that *are* playing in this sound group, and make *them* duck.