Involute Parameterized Gears in 2D

This is a fork of [Leemon Baird's gear generator](http://www.thingiverse.com/thing:5505). It gives you coordinates of a gear in XY plane, rather than a complete 3D model. I made this because I wanted to play with [sweep() and skin() functions](https://github.com/openscad/list-comprehension-demos). example.scad file shows how it works.

Basic functionality is same as the original, so take a look at his [page](http://www.thingiverse.com/thing:5505) if you want more information.