* qatar/master:
  APIChanges: document git revision for CODEC_CAP_SLICE_THREADS addition.
  Introduce slice threads flag.
  FATE: allow forcing thread-type when doing threaded fate runs.
  Use av_log_ask_for_sample() where appropriate.
  error: sort, pack, and align error code and string definitions
  The stabilization period after version bumps should be one month, not one week.
  applehttp: Expose the stream bitrate via metadata
  doc: Add some initial docs on the applehttp demuxer
  Provide a fallback version of the libm function trunc
  libavdevice: Define _XOPEN_SOURCE for usleep
  lavc: provide deprecated avcodec_thread_init until next major version
  lavc: provide the opt.h header until the next bump
  error: change AVERROR_EOF value
  error: remove AVERROR_NUMEXPECTED
  error: add error code AVERROR_OPTION_NOT_FOUND, and use it in opt.c

Conflicts:
	libavcodec/h264.c
	libavutil/error.c
	libavutil/error.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>