Update to 1.2.0

* Buildlink to devel/googletest to test-libvpx (not installed and not tested).

Changelog:
2012-12-21 v1.2.0
  This release acts as a checkpoint for a large amount of internal refactoring
  and testing. It also contains a number of small bugfixes, so all users are
  encouraged to upgrade.

  - Upgrading:
    This release is ABI and API compatible with Duclair (v1.0.0). Users
    of older releases should refer to the Upgrading notes in this
    document for that release.

  - Enhancements:
      VP8 optimizations for MIPS dspr2
      vpxenc: add -quiet option

  - Speed:
      Encoder and decoder speed is consistent with the Eider release.

  - Quality:
      In general, quality is consistent with the Eider release.

      Minor tweaks to ARNR filtering
      Minor improvements to real time encoding with multiple temporal layers

  - Bug Fixes:
      Fixes multithreaded encoder race condition in loopfilter
      Fixes multi-resolution threaded encoding
      Fix potential encoder dead-lock after picture resize

(ryoon)