Original commit message from CVS:
* ext/a52dec/gsta52dec.c: (gst_a52dec_handle_event):
* ext/dts/gstdtsdec.c: (gst_dtsdec_handle_event):
Take filler handling back out. Decoders shouldn't need to.

* gst/mpegstream/gstdvddemux.c: (gst_dvd_demux_handle_dvd_event),
(gst_dvd_demux_handle_discont):
* gst/mpegstream/gstmpegdemux.c: (gst_mpeg_demux_send_discont),
(gst_mpeg_demux_init_stream), (gst_mpeg_demux_send_subbuffer),
(gst_mpeg_demux_synchronise_pads),
(gst_mpeg_demux_sync_stream_to_time):
* gst/mpegstream/gstmpegdemux.h:
* gst/mpegstream/gstmpegparse.c: (gst_mpeg_parse_parse_packhead):
Use a combination of SCR and PTS to detect when a pad needs filler
events.
Fix discont handling so seeking works.