reduce CI_NUM
slicetype: reorg to make frame cost estimates re-entrant (for RC and WP)

* moves frame cost calculations into a separate class deriving from WaveFront
* frames[] array now always declared on stack for better re-entrant behavior
* re-orders functions in slicetype.cpp for clarity
* internal methods were made protected, for documentation purposes only
* fixes a few minor problems discovered during the reorg
* removes deprecated ReferencePlanes.unweightedFPelPlane

--HG--
branch : stable
cleanup initPattern()
Merge with stable

--HG--
extra : amend_source : ace97c3678e0cb2f6b76feb5e084c8256d15e068
slicetype: remove unused numDecided member variable
slicetype: upgrade frame cost variables to uint64_t

--HG--
branch : stable
testbench: added the chroma_addAvg primitives.
Merge with stable
preset: re-disable lookahead at ultrafast preset
slicetype: repair I frame placement with lookahead disabled

if ((true || foo) && bar) properly degrades to if (bar)
white-space and other nits
nit