libvpx: Pull from upstream

Current HEAD: 687c56e8026978f8ccfd5b3fbfee4dbd1de466e1

git log from upstream:
7045aec SAD32xh and SAD64xh for AVX2
7c4992c Remove the dependency in token storing locations
f0c3da9 Alter adjustment of two pass GF/ARF boost with Q.
73ae6e4 Add highbitdepth function for vp9_avg_8x8
e1111fb Remove unused VAR_BASED_FIXED_PARTITION flag
5e766cc Use rate/distortion thresholds to control non-RD partition search
6f77bff Updates to aggressive denoising mode.
e3bf55d Correct the logic of ready_for_new_data.
6356d21 vp9_denoiser_sse2.c: solve windows build error.
e2612fb Add init and reset functions for RD_COST struct
94ecfa3 Reset rate cost value in rd mode search
8514d03 vp9_denoiser_sse2.c: eliminate gcc warnings
50c59cd Adds a set of end-to-end encode tests
ed100c0 Fix an ioc issue in super_block_uvrd
716ae78 Change initialization of static_scene_max_gf_interval.
68b550f [spatial svc]Another workaround to avoid using prev_mi
d5130af Revert "Move input frame scaling into the recode loop"
4680329 Revert "[spatial svc]Another workaround to avoid using prev_mi"
23fc1f7 Fix in bit-shift operation for highbitdepth decode
91657ab fix CONFIG_SPATIAL_SVC warning
09ea74f Some updates for Speed 6/VAR_BASED_PARTITION.

Review URL:

git-svn-id: 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
194 files changed