search: save a few cycles

--HG--
extra : rebase_source : 474ada0297c1b594c8ba03f89828d18ae459e84b
denoiseDct: test bench code
analysis: intra picture estimation (mode and split decision)information  sharing

when --analysis-mode=save - the encoder runs a full encode and dump the
best split and mode decisions into x265_analysis.dat(default file name if file
name is not provided) file
when --analysis-mode=load - the encoder reads the best split and mode decisions
from x265_analysis.dat and bypass the actual split and mode decisions, and
therefore perform a much faster encode
analysis: nits
analysis: add CU specific details to encodeCU()
api: do not reuse the analysisData buffer for more then one picture, set it NULL
add fanout validation module to check param compatibility
frameencoder: fix VBV row resets when SAO is disabled

When SAO is disabled, the row bitstream is generated as CTU analysis progresses.
We must reset the row bitstream after a restart to avoid coding errors.
The CAABAC state is already reset correctly when CTU col 0 is re-coded.