Added collision mesh scaling.

Adds scaling to BulletShapeMeshs on creation, so for instance adding the following to ```test.sc``` (after the ```@ship``` declaration) will cause the in-game ship to be solid.

```
&BulletShapeMesh
>scale=0.1f
>z=-3.0f
>y=0.75f
>x=-18.0f
>meshFile=shipobj/ship.objs
```