This commit combines uniform quantizer with trellis based coefficient
level optimization. It improves the codebase compression performance:

lowres 0.8%
midres 1.0%
hdres  1.6%

Note that the current trellis optimization unit is using C code. This
will make the cost of the overall quantization process slower. A number
of optimizations will come up next.

Change-Id: Id441dd238e4844409d0f08f82604be777f3f5282