Merge remote-tracking branch 'qatar/master'

* qatar/master:
  lavf: simplify is_intra_only() by using codec descriptors.
  lavc: add an intra-only codec property.
  lavc: add codec descriptors.
  lavc: fix mixing CODEC_ID/AV_CODEC_ID in C++ code.
  dict: move struct AVDictionary definition to dict.c
  dict: add av_dict_count()

Conflicts:
	doc/APIchanges
	libavcodec/old_codec_ids.h
	libavformat/utils.c
	libavutil/version.h

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