Merge "Subpel search cleanups and enhancements"

diff --cc vp9/encoder/vp9_encoder.h
Simple merge

diff --cc vp9/encoder/vp9_pickmode.c
Simple merge

diff --cc vp9/encoder/vp9_rdopt.c
Simple merge

diff --cc vp9/encoder/vp9_speed_features.c
Simple merge

diff --cc vp9/encoder/vp9_speed_features.h
Simple merge