[Cin] AdobeRGB and editing

[Andrea paz]

CinGG has no color management. I also have a wide gamut monitor (98%
DCI-P3), but it is useless in CinGG.
We have collected all the color info in the manual:
https://cinelerra-gg.org/download/CinelerraGG_Manual/Overview_on_Color_Managemen.html

PS: If you find any other news or ways of dealing with color in CinGG,
please let us know and we will add it to the manual.