ext/mad/gstid3tag.c: When acting as a muxer, set caps on outgoing buffers and set...

ext/mad/gstid3tag.c: When acting as a muxer, set caps on outgoing buffers and set caps on source pad (fixes #323658)....

Original commit message from CVS:
Patch by: Alexander Lancaster  <alexl at users sourceforge net>
* ext/mad/gstid3tag.c: (gst_id3_tag_get_caps), (gst_id3_tag_init),
(gst_id3_tag_sink_event), (gst_id3_tag_src_link),
(gst_id3_tag_chain):
When acting as a muxer, set caps on outgoing buffers and set caps
on source pad (fixes #323658). Remove unused application/x-gst-tags
cruft from the 0.6 days.