Update the color of all polygons when setting the color to a CSG

[breiler]

After an geometric operation the polygons in the CSG will retain its color information. This change will make it so that if a new color is set on the CSG it will overwrite the colors on all polygons.

Relates to issue #53

[madhephaestus]

I added some code in another PR this morning for you to take a look at. It removes color from the synchronized properties and moves it to a stand alone variable. A reference to this color object is passed to each polygon when set, and then remains there through all the operations by removing the set color calls in the union and difference operations. Take a look at #57