Fat stars

This is a rebased version of #1459, with its history cleaned up slightly. The code changes are the same and aren't very invasive. This is what Epsilon Eridani looks like with its equatorial : polar ratio set to 1.56:

![screenshot-20130401-001538](https://f.cloud.github.com/assets/115749/322515/5f309f8a-9a59-11e2-976b-bbe2cc70baff.png)