Graphics: Remove duplicates

Some time ago those were intended to be rewritten into OSG wrapper, and
since then forgotten.
Physcis: Rename hrenginphysics to physics-bt
Audio: Create OpenAL Soft wrapper

This is only a basic wrapper, but it provides almost the same
functionality as the previous BASS wrapper.

- threaded sound play
	still needs some work, currently consumes excessive cpu power
- WAVE RIFF loader
	no other formats
- sounds are still hardcoded