Merge commit '8655c541'

* commit '8655c541':
  libvpx: Support the vp9 extended profiles

Conflicts:
	Changelog
	configure
	libavcodec/libvpx.c
	libavcodec/libvpx.h
	libavcodec/libvpxdec.c
	libavcodec/libvpxenc.c
	libavcodec/version.h

mostly not merged, as requested by jamrial

See: 01e59d48
See: 079b7f6e and others
Merged-by: Michael Niedermayer <michaelni@gmx.at>