[GRASS5] [bug #3704] (grass) d.rast.arrow does not save a line in the monitor history

[Hamish]

I want to add the ability to disable the grid drawing in d.rast.arrow.
I don't want to go to the trouble of making it support full RGB.

This works, but is it this kosher C?

    opt4->answer     = "gray" ;
    opt4->options    = D_COLOR_LIST ",none" ;


??
Hamish