OpenScad Bezier Function with Ribbons

Perhaps it's bad form to create a derivative of your own thing when it's just a code update rather than an actual 'thing' but...

This thing incorporates a couple more changes to the Bezier functions. First, it adds a 3 element version of the PointOnBezCubic() function. So, there's now 2D and 3D. The 3D version can be used for x,y,z values, or for r,g,b values, as demonstrated in the pictures.

Speaking of pictures, I've added an example of how to use color with the bezier curve to give your images that groovy ramped color goodness. I expect to do very bad things with this.

Some more factoring and commenting of the code should make it fairly easy to understand.

But, all that goodness was added so that I could actually create BezierStrips! Just think of it. You give the function two sets of control points (4 points each), and it will generate an extruded strip that is 'in between' the two curves. Curve1 is on 'top' and Curve2 is on 'bottom', but actually it doesn't matt