Changes for loadCTUData

Replaced getDepthScanIdx() with table g_depthScanIdx
Moved Analysis::loadCTUData to TComDataCU::loadCTUData since it only works with TComDataCU fields
Replaced CU.offsets[2] with local variables in loadCTUData since that is the only place it was set and used
minor changes to reduce the number of local variables in loadCTUData