aarch64: add armv8 CPU flag
aarch64: implement videodsp.prefetch

8% faster h264 decoding on Apple A7.
libxvid: add working lumimasking and variance AQ

The old implementation is unusable due to changes in the Xvid API.
Further fixes by Michael Niedermayer <michaelni@gmx.at>.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
libxvid: Add SSIM displaying through a libxvidcore plugin

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
h264: Refactor decode_nal_units
adler32: Fix doxy group definition

Based on a patch by James Almer <jamrial@gmail.com>.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
xtea: Add Doxy @file and group
Merge commit '8675bcb0addb1c7fb0b04682d1f3f95d5b8dae14'

* commit '8675bcb0addb1c7fb0b04682d1f3f95d5b8dae14':
  aarch64: add armv8 CPU flag

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'd3789eeeed3423bd1ca9dc40030a2f7a21ea5332'

* commit 'd3789eeeed3423bd1ca9dc40030a2f7a21ea5332':
  aarch64: implement videodsp.prefetch

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '5ce7ca68b86856ee8e9d6530dffdadc4eca4f8d1'

* commit '5ce7ca68b86856ee8e9d6530dffdadc4eca4f8d1':
  libxvid: add working lumimasking and variance AQ

Conflicts:
	libavcodec/libxvid.c
	libavcodec/version.h

See: ccb212b6c3ed18c9ff4e0c982574c43f92657f9f
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'c389a804943095ebf078daec6b64690d2c97069c'

* commit 'c389a804943095ebf078daec6b64690d2c97069c':
  libxvid: Add SSIM displaying through a libxvidcore plugin

Conflicts:
	libavcodec/libxvid.c
	libavcodec/version.h

See: 3b3c1ed0768af874c624cc555fbbd1fcea370200
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'e10fd08aa7fbe8645545ad2e8721f0ed03c8e06a'

* commit 'e10fd08aa7fbe8645545ad2e8721f0ed03c8e06a':
  h264: Refactor decode_nal_units

Conflicts:
	libavcodec/h264.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'f73495686d109ffffaa8c0387e790e7997326229'

* commit 'f73495686d109ffffaa8c0387e790e7997326229':
  adler32: Fix doxy group definition

See: 624672fcce84c41e9e2fe9ff3ec3fd56140b175f and others
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  xtea: Add Doxy @file and group

See: 50f52a5498ff02c997d16b8181f32b933ce94b6b
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/h264/find_start_code: factorize addition out

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