Merge pull request #9 from fr500/master

Add shader options and use Ox for windows builds
Call PSP_RunLoopuntil directly - same with AudioMix function
Merge pull request #10 from fr500/master

remove messages
(Libretro) Take out GLU header dependency
(Libretro) Custom optimized version of __sceAudio.cpp - avoids
atomic locking/mutex locking which is totally unnecessary for libretro
(libretro) Rename custom __sceAudio