Write an example that uses a box for a "buggy" with four sphere "tires" on a Planar scene. Use appropriate joints to connect the tires to the buggy.

We don't currently have all the classes and methods needed to make this really good, but a working car should be able to make it work.

The most important part of this task is the comments - you should explain every piece of the code and how it works. This may eventually become part of the PySoy Primer.

While working on this task you should join and remain in #PySoy on Freenode to get help, feedback, and guidance from mentors and other developers.

When you've done, commit your work and post the resulting changeset url to this task.