rem: load_audio_out_driver (GtkXine *gtx, const char *audio_driver_id)
add: load_audio_out_driver (GtkXine *gtx)
context: load_audio_out_driver (GtkXine *gtx, const char *audio_driver_id){	if (strcmp (audio_driver_id, "null") == 0)		return NULL;	return xine_open_audio_driver (gtx->priv->xine,			audio_driver_id, NULL);}