implemented couple of new thread functions: wait and release
winmm & xaudio2: use Thread::wait and Thread::release
looks like I managed to revert thos channels -> voices changes
Thread::wait(): remove time parameter and always use INFINITE with WaitForSingleObject()
refactored XAudio2 back-end. It's hopefully safer and more sensible in general
Merge pull request #3 from tv-s/master

2 new thread functions