api: remove reserved NAL enums and C++ style comments from public header
api: remove hungarian prefixes from x265_nal members

These particular prefixes came from x264 originally
api: remove old suffix and prefix from C symbols in comment, reflow
api: make x265_encoder_get_stats() somewhat future proof

By passing in the size of x265_stats as the user application knows about the
encoder can know not to try to set new fields that were added to the end of
x265_stats.  This requires some discipline on our part to only append to the
structure and to always check the size for any new fields we might add.
api: nit
encoder: simplify size variables
api: cleanup x265_param orderings, add full comments
common: validate --subme value
common: nit
cli: fix warning in CLI help
api: enable b-pyramid by default

The only reason for it to be disabled is if the decoder/use case prevented it
api: fix typos and improve chroma qp offset descriptions
api: enable weightp by default, disable for ultrafast
asm: code for transpose4x4 routine
asm: code for transpose_8x8 routine
asm: code for transpose_16x16 routine
TComYuv::copyToPicLuma, blockcopy_pp asm integration
TComYuv::copyPartToPartChroma, blockcopy_pp asm integration
csp support for blockcopy_ps
TComYuv::copyPartToPartChroma, blockcopy_ps asm integration