refine depth related.

maxCUDepth:	CU depth
maxFullDepth:	CU+TU or CU+PU depth
unitSize:	always 4
encoder: remove m_maxCuDQPDepth, simplify dqp logic
Merge with stable
entropy: simplify EstBitsSbac

There was no reason for significantBits to be a different type than all the
other fix15 bit costs. And NUM_QT_ROOT_CBF_CTX is 1
entropy: pass bIsLuma to estBit() instead of limited TextType range

if the only options were TEXT_LUMA or TEXT_CHROMA, it is better to use a
bool argument and avoid ambiguity about TEXT_CHROMA_U or TEXT_CHROMA_V
quant: combine psy-rdoq scale and lambda into one variable

Reduces the number of 64bit multiplies required per psy-value
evaluation
cli: update psy-rdoq rangw in CLI help
param: add psy-rd and psy-rdoq to param2string (for info SEI and stats file)
cli: fix help syntax
param: typo
Merge with stable