fix emms: move selectLambda() into xRateDistOptQuant() and issue emms before it
split rate calculation functions to luma and chroma to simplify luma path
remove redundant memset
TEncSearch: limit AMVP loop bounds in xCheckBestMVP

entries in the table beyond m_num were not initialized
Merge with stable
TComDataCU: remove redundant refIdx check from fillMvpCand

fillMvpCand is only called from one place and the refIdx will always be
positive
TEncSearch: nit