me: build a larger list of motion candidates for ME (closes #14)

--HG--
extra : rebase_source : cd9bbbeb6557b8dcd383993d23426a43b6a7af43
TComDataCU: nits, assume sizeof(char) == sizeof(uint8_t)

cleanup white-space and hungarian prefixes

--HG--
extra : rebase_source : 6fc226718a586aea151426e63fdaad419b14d3ab
adapt x264 style lambda tables [CHANGES OUTPUTS]

initLambda() in TComRom.cpp is passed the scale factor that is used to adjust
lambda2 values. It uses 0.85 right now, which is similar to x264's value (0.9),
and seems to be optimal for HEVC based on our tests.

These lambda tables seem to help most at low QPs, allowing the encoder to get
nearly lossless quality at high bitrates.

--HG--
extra : rebase_source : 2064f930689640ff76226c296c83a720fb8c0ae5
slicetype: use a worker thread for slicetypeDecide when it may help (closes #17)

If slicetype/scenecut analysis is enabled and the user has a thread pool of at
least 4 threads, use a worker thread to run slicetypeDecide.

Improves performance in presets that were bottlenecked by b-adapt 2 style
lookahead complexity.

--HG--
extra : rebase_source : e91878a490c96e217d9125eeb2830dfe17520014
fix preset placebo option crash for 444 color format
rest: update --qp docs to mention behavior of --qp 0
rest: improve description of constrained intra
rest: remove redundant `in`
rest: improve VUI docs
cli: fix bitrate output when encoding
log: do not report weightb twice
slicetype: rowsCompleted variable should be volatile

Don't allow a compiler to optimize out the reads, it would cause a deadlock