Merge remote-tracking branch 'qatar/master'

Merge remote-tracking branch 'qatar/master'

* qatar/master:
  lavf: pass options from AVFormatContext to avio.
  avformat: Use avio_open2, pass the AVFormatContext interrupt_callback onwards
  avio: add avio_open2, taking an interrupt callback and options
  avio: add support for passing options to protocols.
  avio: add and use ffurl_protocol_next().
  avformat: Pass the interrupt callback on to chained muxers/demuxers
  avio: Add an AVIOInterruptCB parameter to ffurl_open/ffurl_alloc
  avformat: Use ff_check_interrupt
  avio: Add an internal utility function for checking the new interrupt callback
  avio: Add AVIOInterruptCB
  texi2html: remove stray \n
  doc: prettyfy the texi2html documentation
  swscale: handle unaligned buffers in yuv2plane1

Conflicts:
	libavformat/avformat.h
	libavformat/avio.c
	libavformat/mov.c

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