Yet another Bezier library for OpenSCAD

This is yet another Bezier library, which takes a list of nodes and control points and generates a list of points that you can then feed into polygon() or some other function. The Bezier curves can be either 2D or 3D, but I've only been using it for 2D.

The library is designed so one can lay out 2D Bezier curves basically in one's head. But if you prefer to lay them out graphically, you can use Inkscape plus [this plugin](https://www.thingiverse.com/thing:3527642) to design Bezier curves for