Original commit message from CVS:
2005-10-25 Julien MOUTTE <julien@moutte.net>
* ext/libpng/gstpngdec.c: (user_info_callback),
(gst_pngdec_caps_create_and_set), (gst_pngdec_task): Temporary
hack to get correct colors order when we have a png image with
alpha channel.