SGModel: Wave conversion

This is a very basic conversion of the Wave ship. The wheels have been replaced with feet. I really like the basic Wave design -- it's really clean. The mesh could do with some cleaning up in places (particularly for the lower quality version). Currently, the landing legs/feet are untextured.

I had a big of problem with docking, I don't know if this is a problem with the collision mesh or a bug. Currently, the collision mesh just has three quads at the bottom of the feet. Perhaps it's important for these to be extended to cubes to make the collision shape a volume rather than a thin plane?

Here it is sitting on the pad at Olympus Mons:

![screenshot-20130131-022602](https://f.cloud.github.com/assets/115749/113340/9870a884-6b4d-11e2-8390-c7445fb069c4.png)