[GRASS5] Suggested color function names

[Hamish]

>  Also, add:
> 
> 	typedef RGBA_Color RGB_Color;
> 
> and use RGB_Color for functions which ignore the alpha component.

A good idea, but in include/ we already have

devlib.h:int RGB_color(unsigned char, unsigned char, unsigned char);
devlib.h:int Set_RGB_color(unsigned char,unsigned char,unsigned char);

(afaict devlib.h is not used by anything. unneeded copy from GRASS 5??)

graphics.h:#define RGB_COLOR                   6
graphics.h:#define RGB_COLORS                  52


I think it is confusing to have both RGB_Color and RGB_COLOR around.

also display/d.vect/plot.h has a rgb_color struct, but that is easy to
change to use RGBA_Color (or similar), or remove lookup table & set in
the main libs? (here d.vect random color defaults, purposefully
non-primary colors)


Hamish