Living hinge

This is a customizable Living Hinge, which I think was invented by http://www.thingiverse.com/SNIJLAB/about. The Customizer is designed to give people a feel for what my program can do. The idea for this is to simply add a living hinge in OpenSCAD with a function, and output a DXF that can be sent to a laser cutter.

The following parameters are customizable:
length = the y dimension of the hinge, parallel to the laser cuts
width = the x dimension of the hinge, transverse to laser cuts
d=t