Physicalize() calculates colission mesh on unscaled object.

```
obj = loadGeometry("obj.dae")
obj.setScale(0.2,0.2,0.2)
obj.physicalize(1,0,0)
```

Creates a collision mesh only on the unscaled object. The mesh is not visualized, but it collides with other objects. Rotation `obj.rotate(x,y,z)` seems to be working.

Concave hulls do not seem to work (even without scale). (`obj.physicalize(1,0,1)` should do it, right?)
