New color picker

[fowler]

The checked-in geomview code now has a colorwheel instead of RGB
sliders on the color panel.  panel.fd and glui.c changed.  An
inconvenient side effect of this is that the next Geomview release
will have to take the colorwheel code (patches to FORMS) along with
it.  If this is unacceptable, we could make it into a free object
(which it was originally anyway) or go back to the sliders.

Also, the bounding boxes in the current Geomview code seem to be
rather stubborn about turning on and off.

I installed crayola and warp - please tell me if you find bugs.
-Celeste