use std::swap() for readability
entropy: remove m_ prefix from struct TURecurse members
entropy: replace SBac and TEncSearch methods with TURecurse methods

Both classes had nearly the exact same methods for managing this external
structure.  how wierd?
TEncSearch: nits
entropy: convert initSection into a constructor, since it was used as such
merge CABAC into SBac class
entropy: hoist trivial functions for later optimizations
entropy: nits
TComTrQuant: rename estBitsSbacStruct to EstBitsSbac
entropy: remove include of TComSampleAdaptiveOffset.h
entropy: re-order methods again for better clarity, make many private
entropy: nits