Merge commit 'f8b1e665'

* commit 'f8b1e665':
  avconv: print info/capabilities options in a separate help group.
  avtools: add -h demuxer/muxer
  cmdutils: extend -h to allow printing codec details.

Conflicts:
	cmdutils.h
	ffmpeg_filter.c
	ffmpeg_opt.c
	ffplay.c
	ffserver.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>