- Fix the over-writing bug in horizontal filtering as width = 2.
- Fix 10-tap vertical filtering which no longer reads one row of
  pixel above the block.
- Fix 10-tap filter zero padding.
- Encoder speed slow down ~4.0%, compared to,
  81ad9536 Convolution vertical filter SSSE3 optimization

Change-Id: I9bb294a4529300081c29bf284e6bc6eb081cc536