ext/dv/gstdvdec.c: Fix caps nego and pad templates. RGB mode caps should work now.

ext/dv/gstdvdec.c: Fix caps nego and pad templates. RGB mode caps should work now.

Original commit message from CVS:
* ext/dv/gstdvdec.c: (gst_dvdec_video_link):
Fix caps nego and pad templates. RGB mode caps should
work now.
* ext/dvdnav/gst-dvd:
Move mpeg2dec inside the thread because otherwise the
queue rejects cap changes mid-stream
* ext/mpeg2dec/gstmpeg2dec.c: (gst_mpeg2dec_get_type),
(gst_mpeg2dec_flush_decoder):
For mpeg2dec > 0.4.0, call the flush function instead of
manually extracting all in-flight frames.
* ext/raw1394/gstdv1394src.c: (gst_dv1394src_factory),
(gst_dv1394src_init), (gst_dv1394src_iso_receive):
Change mime type video/dv go video/x-dv to match the
rest of gst-plugins