Merge "Enable adaptive prediction mode coding" into nextgenv2

diff --cc vp10/common/blockd.h
Simple merge

diff --cc vp10/encoder/bitstream.c
Simple merge

diff --cc vp10/encoder/block.h
Simple merge

diff --cc vp10/encoder/encodeframe.c
Simple merge

diff --cc vp10/encoder/rdopt.c
Simple merge