Leaking colormap entries

[DaveFlater]

Coming from: commit 2d895e9
"Remove XftColorFree call that happens only when not needed"

Neither XftColorFree nor XFreeColors is called anywhere. With a PseudoColor visual, Xaw3dXftDrawString potentially leaks a colormap entry every time someone changes foreground, insensitive_twist, text_bg_hilight_color, or text_fg_alternate_color (via colorSwitch). ThreeD and SmeThreeD similarly leak colormap entries whenever the shadow colors change.