gst/realmedia/rmdemux.c: Do fragment collection in the demuxer so that we can now...

gst/realmedia/rmdemux.c: Do fragment collection in the demuxer so that we can now work with both ffmpeg and realvideo...

Original commit message from CVS:
* gst/realmedia/rmdemux.c: (gst_rmdemux_reset),
(gst_rmdemux_chain), (gst_rmdemux_parse_mdpr),
(gst_rmdemux_fix_timestamp), (gst_rmdemux_parse_video_packet),
(gst_rmdemux_parse_audio_packet), (gst_rmdemux_parse_packet):
Do fragment collection in the demuxer so that we can now work with
both ffmpeg and realvideodec to decoder real video content.