* commit 'd78fd2fa':
  Add MagicYUV decoder

Changes observed from Libav:
- many cosmetics (function renames/move, spacing, line breaks)
- MagicYUVContext.slices_size is now unsigned
- use of pixdesc (include fixed in FFmpeg)
- mention of "Lossless" in the long name dropped (also removed from
  general.texi in FFmpeg)
- addition of the FF_CODEC_CAP_INIT_THREADSAFE caps
- use of qsort() instead of AV_QSORT() (NOT MERGED)
- use of AVCodecContext.{width,height} instead of AVCodecContext.coded_{width,height} (NOT MERGED)

See also 77f9c4b7Merged-by: Clément Bœsch <u@pkh.me>