MIPS: detect mips32r6 and disable mips32r1 code

Change-Id: Id1325c789a990c9a8704e84e99a22d580303eb8a
Merge "MIPS: detect mips32r6 and disable mips32r1 code"
Update PATENTS to reflect s/VP8/WebM/g

Sync with http://www.webmproject.org/license/additional/

modified:   PATENTS

Change-Id: I9f7af36fdcf57a82311363a043707b181832fc18
MIPS: mips32r2: added optimization for BSwap32

gcc < 4.8.3 doesn't translate bswap optimally.
use optimized version always

Change-Id: I979ea26ad6dc0166d3d2f39c4148eb8adfb7ddec
configure: add work around for gcc-4.9 aarch64 bug

add -frename-registers to avoid:
src/dsp/dec_neon.c:1234:1: internal
compiler error: in simplify_const_unary_operation, at
simplify-rtx.c:1539

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62040
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61622
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=757738

Change-Id: I52fb3a29ac30b82b27da05378bdb495ddebb97d7
MIPS: dspr2: Optimization of some simple point-sampling functions

Change-Id: I6a4ab29bd0cc5a2951a8882cf9997032dc38bd79
Merge "configure: add work around for gcc-4.9 aarch64 bug"
MIPS: dspr2: added optimization for (un)filters

HorizontalFilter
VerticalFilter
GradientFilter
HorizontalUnfilter
VerticalUnfilter
GradientUnfilter

Change-Id: I54055b4767c37719691811072e95bf79c1f627b1
Add smart RGB->YUV conversion option -pre 4

New function: WebPPictureSmartARGBToYUVA()
This implement smart RGB->YUV conversion.

This is rather undocumented for now, and is triggered using '-pre 4'
preprocessing option.

This is slow-ish and use quite some memory, but should be improvable.
This is somehow a usable beta version.

Change-Id: Ia50a8c30134e4cab8a7d3eb70aef13ce1f6187a1
Merge "Add smart RGB->YUV conversion option -pre 4"
faster RGB->YUV conversion function (~7% speedup)

with a special case for dithering==0., it gets somewhat faster on x86
thanks to inlining.

Also, less macros.

Change-Id: Ic2f2bf6718310743bb40cef2104fa759a073e6d5