- first pass of refactoring of three.csg (exporting csg data to three.geometry) is done!
 * over 50 x faster than previous implementation ! wooh!
 * speed increase based on using an index of vertices/vertex numbers
 * still need to add tesselation for polygons with more than 3 vertices ( a lot of meshes will apear as if having holes in them)
 * manually tested a few of the overal geometry/csg operation limits of coffeescad : while rather complex meshes with lots of polygons can be displayed easilly
csg operation fail (most of the time silently?) need to investigate
- triangulation of csg meshes now done (see previous commit), new (faster) version of csg to three done