cli: change --log option to --log-level, allow strings or ints

getopt allows partial matches, so --log N will still work like it always has.
x265_parse_param() will accept "log" or "log-level"

Since the first entry in the name list corresponds to -1, the string list is
not placed in x265.h, where all indices are 0 based.
cli: improve CLI help for --overscan
cli: improve help text by describing command argument data types
cli: fix AQ CLI help.  0, 1, and 2 are valid options
cli: add --no- options to some VUI fields

This is a little pedantic since they default to false and likely won't change
at any time.
cli: reorder help for better clarity
cli: show condensed error message if no arguments are given
cli: invalid preset or tune is a non-recoverabe error
cli: show compiled assembly status and detected SIMD arches on x265 --version
cli: add --crf-max option for param.rc.rfConstantMax