Merge remote-tracking branch 'qatar/master'

* qatar/master:
  ARM: ac3: update ff_ac3_extract_exponents_neon per 8b7b2d6a
  ARM: NEON optimised vector_clip_int32()
  swscale: disable full_chroma_int when converting to non-24/32bpp RGB.
  suggest to use av_get_bytes_per_sample() in av_get_bits_per_sample_format() doxy
  ffmpeg: use av_get_bytes_per_sample() in place of av_get_bits_per_sample_fmt()
  put_bits: remove ALT_BITSTREAM_WRITER
  put_bits: always use intreadwrite.h macros
  libavformat: Add an example how to use the metadata API
  doxygen: Prefer member groups over grouping into modules
  doxygen: be more permissive when searching for API examples
  avformat: doxify the Metadata API
  lavf: restore old behavior for custom AVIOContex with an AVFMT_NOFILE format.
  lavf: use the correct pointer in av_open_input_stream().
  avidec: infer absolute vs relative index from first packet

Conflicts:
	libavformat/Makefile
	libavformat/avidec.c

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