cu: style nits, no behavior change
cu: pass m_cuLocalData to loadCTUData()

This is prep-work for removing m_cuLocalData from TComDataCU and having only
a few instances of the array.
cu: remove m_cuLocalData from CU, use child offsets instead of absolute indices

This commit also removes a redundant 'tld.analysis.m_quant.setQPforQuant()'
from frameencoder.cpp. This belonged in compressCTU() and was actually one of
the first things it does.
cu: repair original intent of getLastCodedQP(), fix 73c6c9086577
cu: remove unused enum NDBFBlockBorderTag
cu: inline single use of setSubPart into setInterDirSubParts
cu: use memset in setQPSubParts()
cu: nits
frameencoder: group pointer members together for better alignment
frameencoder: pre-calculate the set of unique geoms for the picture size

Now the geom sets only need to be calculated once, and they occupy a minimum
amount of memory.
encoder: improve comment, frame encoders to not use the worker pool