[Ohrrpgce] SVN: teeemcee/11903 rgb_to_string and string_to_rgb now print/read the alpha component too;

[subversion at HamsterRepublic.com]

teeemcee
2020-07-18 19:10:36 -0700 (Sat, 18 Jul 2020)
208
rgb_to_string and string_to_rgb now print/read the alpha component too; add RGBcolor string cast operator (calls rgb_to_string)

Alpha isn't printed if it's 255. And alpha is still ignored by string_to_color.
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U   wip/common.rbas
U   wip/surface.bi