Fix some more docs.

Fix some more docs.

Original commit message from CVS:
* docs/plugins/Makefile.am:
* docs/plugins/gst-plugins-base-plugins-docs.sgml:
* docs/plugins/gst-plugins-base-plugins-sections.txt:
* ext/gnomevfs/gstgnomevfssink.h:
* ext/gnomevfs/gstgnomevfssrc.h:
* ext/vorbis/vorbisdec.c: (vorbis_handle_data_packet):
* ext/vorbis/vorbisdec.h:
* ext/vorbis/vorbisenc.c: (gst_vorbisenc_convert_sink):
* ext/vorbis/vorbisenc.h:
* ext/vorbis/vorbisparse.c: (vorbis_parse_set_header_on_caps),
(vorbis_parse_chain), (vorbis_parse_change_state):
* ext/vorbis/vorbisparse.h:
* gst/audioconvert/gstaudioconvert.h:
* gst/tcp/gsttcpserversink.h:
* gst/videotestsrc/gstvideotestsrc.c:
* gst/videotestsrc/gstvideotestsrc.h:
* gst/volume/gstvolume.c:
* gst/volume/gstvolume.h:
Fix some more docs.
Added docs for vorbisdec and vorbisparse.
Fix vorbisparse.