FreeCAD sketch to OpenSCAD script

I like the idea of constrained sketches available in FreeCAD. This is a hack to transfer them to OpenSCAD without too much trouble.

This Thing is an adaptation of Dan Newman's excellent Inkscape plugin (parent Thing). The main changes are:

1) Runs without input and saves .scad in the same folder as .svg file (see instructions below)

2) Does not extrude shapes, but keeps them two-dimensional

3) Ignores some transformations, and units, to get same size in OpenSCAD units as in the FreeCAD sketch.

4) Minor technical changes to circumvent ugly crash bugs in Inkscape (and FreeCAD's svg export, I think)