libvpx

Merge changes I2e0cc72a,I63a7da78,I4aee2600,I71113505,I3dce6c70, ...

* changes:
  Only build multithreaded functions on mt builds.
  Don't build calc_psnr for high bit depth.
  Enable missing dual lpf test
  Remove unused VP10 functions.
  Mark VP10 functions as 'INLINE'
  Remove unused functions from test files
  Only build append_negative_gtest_filter when it is used.
  Add INLINE decoration to static test functions