build: Add config option for CABAC code

This allows for more elegant dependency and object declarations.
libx265: Write global extradata when requested

Matroska, MP4, and other containers require it.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
libx265: Only use one memcpy for headers

They're guaranteed by the x265 API to be contiguous in memory.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Merge commit '8ef33497a6a3ed05d2f931809c074ef3d1878834'

* commit '8ef33497a6a3ed05d2f931809c074ef3d1878834':
  build: Add config option for CABAC code

Conflicts:
	configure
	libavcodec/Makefile

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '60728e8bab8d2a5f6bbb4baa7d53142dbc6047ed'

* commit '60728e8bab8d2a5f6bbb4baa7d53142dbc6047ed':
  libx265: Write global extradata when requested

See: dded5ed9c5eb0c3d5a953e661ea21a9019e93ea4
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  libx265: Only use one memcpy for headers

See: ecb5b9c098009787e02f6de9e2d3e1786531c2f2
Merged-by: Michael Niedermayer <michaelni@gmx.at>
dox/scaler:fix bicubiclin typo

See Ticket3486

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