OpenSCAD Awesome 2D Rectangle Curved Edge Generator

This is a very similar (and awesome, simple) code to, OpenSCAD Awesome 3D Rectangular Prism Curved Edge Generator (see bottom of info for link). It is almost exactly the same as it, but in 2D! Great for laser cutters and CNC machines! This code lets you change the roundness of the edges of the prism to almost anything you want. Feel free to copy and paste and implement this into any of your code, and use it how ever you want. I find this code very useful for simple object design. Check out the 3D version of this at http://www.thingiverse.com/thing:780012 .