check for sdl_image and sdl_mixer versions
use revision number for hedgewars version
LIBRARY "openalbridge"
EXPORTS
openal_init
openal_close
openal_ready
openal_loadfile
openal_toggleloop
openal_setvolume
openal_setglobalvolume
openal_togglemute
openal_fadeout
openal_fadein
openal_fade
openal_playsound
openal_pausesound
openal_stopsound