This minimize code differences between AOM master and nextgenv2

Change-Id: If144865bdf3ef0818e7aac11018b9e786444c550

Cherry-Picked the following commits:
0defd8f2 Changed "WebM" to "AOMedia" & "webm" to "aomedia"
54e66767 Replace "VPx" by "AVx"
5082a369 Change "Vpx" to "Avx"
7df44f17 Replace "Vp9" w/ "Av1"
967f722f Remove kVp9CodecId
828f30ce Change "Vp8" to "AOM"
030b5ffc AUTHORS regenerated
2524caee Add ref-mv experimental flag
016762be Change copyright notice to AOMedia form
81e55269 Replace vp9 w/ av1
9b94565b Add missing files
fa8ca9f2 Change "vp9" to "av1"
ec838b76  Convert "vp8" to "aom"
80edfa01 Change "VP9" to "AV1"
d1a11fb9 Change "vp8" to "aom"
7b582513 Point to WebM test data
dd1a5c8d Replace "VP8" with "AOM"
ff00fc0f Change "VPX" to "AOM"
01dee0bb Change "vp10" to "av1" in source code
cebe6f0c Convert "vpx" to "aom"
17b05679 rename vp10*.mk to av1_*.mk
fe5f8a8a rename files vp10_* to av1_*

Change-Id: I6fc3d18eb11fc171e46140c836ad5339cf6c9419

Manually cherry-picked commits:
ceef0583 libvpx->libaom part2
3d26d916 libvpx -> libaom
cfea7dd7 vp10/ -> av1/
3a8eff73 Fix a build issue for a test
bf4202ed Rename vpx to aom

Change-Id: I1b0eb5a40796e3aaf41c58984b4229a439a597dc

Change-Id: I0d1e439b75eb749dd80a86474ac5f494478d0360

Change the name of source files to replace "vpx" with "aom".
Change occurences of "vpx" in the code to "aom".

Change-Id: I002c0eaa2c350cf1a895bf01bea5788c61328027

Change-Id: I5629de7726c65fb1463dff5fc5c1c82a3862a8f9

Change-Id: Ibc7933fba85feeb30ef9b14b302d932aff19f54e

The y4m extension used is the same as the one used in ffmpeg/x264.
The patch is adapted from the highbitdepth branch.

Also adds unit tests for y4m header parsing and md5 check
of the raw frame data, as well as y4m writing.

[build fix for Mac/VS by not using tuples with strings]

Change-Id: I40897ee37d289e4b6cea6fedc67047d692b8cb46

Reverting "Adds support for reading and writing 10/12-bit y4m" for now because of Mac Build Failure.

This reverts commit 82dc1332

Change-Id: I824bf42bf47c7df6985c79e451d6af913030d374

The y4m extension used is the same as the one used in ffmpeg/x264.
The patch is adapted from the highbitdepth branch.

Also adds unit tests for y4m header parsing and md5 check
of the raw frame data, as well as y4m writing.

Change-Id: Ie2794daf6dbafd2f128464f9b9da520fc54c0dd6

Fix of https://code.google.com/p/webm/issues/detail?id=698 issue.

Change-Id: I7a92d91481dbbae28d8953f146e9faafdcd7a310

Change-Id: I5164df72aff84eca0ace56032c5373f04053c6a5

Change-Id: I03f614872167841515a74740d654c008b60104a4

This commit setups a test framework for real-time coding. It enables
a light motion search for non-RD mode decision purpose.

Change-Id: I8bec656331539e963c2b685a70e43e0ae32a6e9d