* Much improved, slower edge collapse weighting method that makes this script about 2.5x slower, but brings it up to the quality of qslim (lightwave's decimator), without the manifold' errors.
Probably worth adding a UI front end to this function.
Isnt intended to be ultra high quality, more for automatic realtime "Level of Detail" model generation.
BPyMesh.redux(ob, 0.5) # To reduce to about half the polys