entropy: nits
Remove MAX_TLAYER and stop pretending we can code multiple temporal layers

This simplifies a great many things; enabling further simplications to come.
This commit leaves a sprinkling of TODOs for further cleanups
encoder: remove redundant member variables
slice: simplify max AMP level determination
slice: remove unused m_interRPSPrediction from TComReferencePictureSet
defs: remove some dead definitions, cleanup a comment
remove unused multiple HRD parameter sets from VPS class
frameencoder: nits
entropy: remove broken X265_CHECK
vps: remove m_VPSId, signal hard-coded 0
sps: hard-code an SPS ID of 0, we only ever use one SPS
vps: remove unused m_maxNuhReservedZeroLayerId, m_numOpSets

The values were all hard-coded
vps: remove now unused m_layerIdIncludedFlag
vps: remove remaining set/get methods
vps: remove m_maxLatencyIncrease, it was always 0
entropy: nits
entropy: de-hungarian codePredWeightTable(), fix comments (remove redundants)
ptl: remove hard-coded m_profileSpace
change ProfileTierLevel to a struct, no m_ prefixes
slice: nits