Used OpenAL as only backend for sound.

DirectSound path done via OpenAL.
Removed support of features: EAX 4.0, X-RAM.
All environment effects (reverb, occlusion, etc.) done via EFX.
Removed new cvar s_force_efx.
Fixed very short but noticable shakes of screen.
Made separate project for each third-party library.
Replaced regular libjpeg with libjpeg-turbo.