vf_interlace: do not process an already interlaced frame

Signed-off-by: Anton Khirnov <anton@khirnov.net>
lavc: mark deprecated AVCodec.max_lowres for removal on next bump
Native VP9 decoder.

Authors: Ronald S. Bultje <rsbultje gmail com>,
         Clement Boesch <u pkh me>
VP9 MC (ssse3) optimizations.

Decoding time of ped1080p.webm goes from 20.7sec to 11.3sec.
Full-pixel MC functions.

Decoding time of ped1080p.webm goes from 11.3sec to 11.1sec.
Merge commit '06e7301a2efa8dededecbe6836ee5b59bf7e5e76'

* commit '06e7301a2efa8dededecbe6836ee5b59bf7e5e76':
  vf_interlace: do not process an already interlaced frame

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

* qatar/master:
  lavc: mark deprecated AVCodec.max_lowres for removal on next bump

Conflicts:
	libavcodec/avcodec.h

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

* rbultje/master:
  Full-pixel MC functions.
  VP9 MC (ssse3) optimizations.
  Native VP9 decoder.

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