Merge remote-tracking branch 'qatar/master'

* qatar/master:
  dwt: Drop unused functions spatial_compose{53|97}i()
  nutdec: Remove unused and broken debug function stub
  avcodec: Drop long-deprecated imgconvert.h header
  Add Opus support to the Ogg muxer.
  Add Opus codec id and codec description.
  avformat: Identify anonymous AVIO typedef structs.

Conflicts:
	libavcodec/avcodec.h
	libavcodec/codec_desc.c
	libavcodec/imgconvert.h
	libavcodec/version.h
	libavformat/oggenc.c
	libavformat/version.h

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