- Wrote function: fidtx8_sse2() and fidtx16_sse2().
- Turned on vp10_fht8x8_sse2()/vp10_fht16x16_sse2() for new types.
- Updated 8x8/16x16 unit tests for accuracy/speed.
- Running 20K times with random numbers and getting through
  tx type from V_DCT to H_FLIPADST, SSE2 speed improvement:
  8x8: ~131%
  16x16: ~66%

Change-Id: Ibbb707e932a08fec3b1f423a7dab280a1d696c9a