[x265] [PATCH] cli: Accept new color primaries as per revised HEVC spec

[Vittorio Giovara]

Hello,
with the standard expansions and several new options being added, I
would like to propose a "de-facto" standard in option names to
simplify integration and deploying of open source coding tools.
Especially for well known options, such as color properties, there is
little value in offering different names than what other tools already
use, while on the other hand using the same names everywhere will
simplify developers' life, as well as users'.

Right now x264 and ffmpeg use exactly the same names, as defined in
these tables https://github.com/FFmpeg/FFmpeg/blob/master/libavutil/pixdesc.c#L2251-L2306:
API users will see them, ffprobe will print them, x264 will encode
them. Originally they were also designed to being compatible with
x265.

However since last year new additions, the new options names are
becoming incompatible with that list, and with new options being added
(https://gist.github.com/Adsun701/472ec93957289f057e0c90599ec4bb9a) I
think it's would be beneficial to restore the compatible names and
mandate compatibility with the ffmpeg/x264 list.
I opened a bug/feature request as soon as I noticed
(https://bitbucket.org/multicoreware/x265/issues/348/add-aliases-for-smpte-st-2084-and-smpte-st)
but unfortunately it laid dormant for some time.

Please consider changing the color properties names to the compatible
ones, or add alternative options that can be easily used across
projects.

Best regards
-- 
Vittorio