Update libvpx and incorporate new build system

Move libvpx down a directory. Separate libwebm and rename it. It would
be more accurate to rename external/libvpx to external/webm.

Use file lists directly from upstream libvpx. This allows adding new
targets and new features (such as the encoder) easily. MIPS and x86
options are in progress. See new file "UPDATING"

The new libvpx checkout is not from a release branch. The decoder is
stable but it should be checked and potentially updated if the encoder
is enabled.

Requires I42b51e2845a696a6e211dde00951afc8f571336f which updates
libstagefright to account for new paths and library names.

Change-Id: I739f99d48b8d7e6354c416ef2ca79c954826307f
Update libvpx and incorporate new build system

Move libvpx down a directory. Separate libwebm and rename it. It would
be more accurate to rename external/libvpx to external/webm.

Use file lists directly from upstream libvpx. This allows adding new
targets and new features (such as the encoder) easily. MIPS and x86
options are in progress. See new file "UPDATING"

The new libvpx checkout is not from a release branch. The decoder is
stable but it should be checked and potentially updated if the encoder
is enabled.

Requires Iec8566bce0a4763a9a17b4a46f15aa39b5bcd141 which updates
libstagefright to account for new paths and library names.

Change-Id: I2c0a87b0fc049e855e21f455b806287b578091de
Merge "Update libvpx and incorporate new build system"
am 3ad4b9ab: Merge "Update libvpx and incorporate new build system"

* commit '3ad4b9abde1514ab4a7a30b2eb4a5ef65821463f':
  Update libvpx and incorporate new build system
Enables encoder for libvpx.

Based on libvpx v1.2.0 this change removes the
disable-encoder flags from all build configurations
thus enabling encoder and updates other build
files in accordance with UPDATING.

Change-Id: Ief7c74593fc4a585d4a8b1768a4e1008547f0c40
Signed-off-by: Kunter Gultekin <kuntergultekin@google.com>
Merge tag 'android-4.3_r2.1' into jellybean-mr2.1

Android 4.3 release 2.1