libgba stable release 20060410

libgba has had some minor tweaks that are worth sharing.
http://sourceforge.net/project/showfiles.php?group_id=114505&package_id=124007&release_id=408638

use __asm instead of asm to allow -std=c99
added pn8 compatible macros to gba_sound.h, gba_sprites.h & gba_video.h