Merge remote branch 'qatar/master'

* qatar/master: (37 commits)
  In avcodec_open(), set return code to an error value only when an error occurs instead of unconditionally at the start of the function.
  lavc: remove reference to opt.h from Makefile.
  prefer avio_check() over url_exist()
  avio: remove AVIO_* access symbols in favor of new AVIO_FLAG_* symbols
  lavu: remove misc disabled cruft
  lavu: remove FF_API_OLD_IMAGE_NAMES cruft
NOT PULLED  lavu: remove FF_API_OLD_EVAL_NAMES cruft
  lavc: remove misc disabled cruft.
  lavc: remove the FF_API_INOFFICIAL cruft.
  lavc: remove the FF_API_SET_STRING_OLD cruft.
  lavc: remove the FF_API_USE_LPC cruft.
  lavc: remove the FF_API_SUBTITLE_OLD cruft.
  lavc: remove the FF_API_VIDEO_OLD cruft.
  lavc: remove the FF_API_AUDIO_OLD cruft.
  lavc: remove the FF_API_OPT_SHOW cruft.
  lavc: remove the FF_API_MM_FLAGS cruft.
  lavf: remove misc disabled cruft.
  lavf: remove FF_API_INDEX_BUILT cruft
  lavf: remove FF_API_URL_CLASS cruft.
  lavf: remove FF_API_SYMVER cruft
  ...

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