Replace tx_size prune with the new curvefit model
Replace tx_size prune with the new curvefit model

The thresholds are made somewhat tighter than before.

A slight improvement in coding efficiency and seems about
5% faster on certain sequences.

STATS_CHANGED

Change-Id: If86c2d1d9ba9bcba346417e236f837aa36364c55

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom