GL_APPLE_rgb_422
http://www.opengl.org/registry/specs/gl/APPLE/rgb_422.txt
GL_APPLE_rgb_422
	GL_UNSIGNED_SHORT_8_8_APPLE 0x85BA
	GL_UNSIGNED_SHORT_8_8_REV_APPLE 0x85BB
	GL_RGB_422_APPLE 0x8A1F