GL_NV_texture_compression_s3tc
http://www.opengl.org/registry/specs/NV/texture_compression_s3tc.txt
GL_NV_texture_compression_s3tc

	GL_COMPRESSED_RGB_S3TC_DXT1_NV 0x83F0
	GL_COMPRESSED_RGBA_S3TC_DXT1_NV 0x83F1
	GL_COMPRESSED_RGBA_S3TC_DXT3_NV 0x83F2
	GL_COMPRESSED_RGBA_S3TC_DXT5_NV 0x83F3
