documenting auto*sink using strstr for the video sink lookup, class field is not ordered update other plugins

Original commit message from CVS:

* docs/plugins/Makefile.am:
* docs/plugins/gst-plugins-good-plugins-docs.sgml:
* docs/plugins/gst-plugins-good-plugins-sections.txt:
* gst/autodetect/gstautoaudiosink.c:
(gst_auto_audio_sink_base_init):
* gst/autodetect/gstautovideosink.c:
(gst_auto_video_sink_base_init),
(gst_auto_video_sink_factory_filter):
documenting auto*sink
using strstr for the video sink lookup, class field is not ordered

update other plugins