Jail fixes for issue #12

Here's the revised fixes for this issue. I had to rework a couple of things as I did notice a bug with my previous code, in that it would show a wheel user no matter the shell type, so I got that fixed up as well. 
![screenshot from 2013-06-16 16 12 20](https://f.cloud.github.com/assets/3308274/659857/7d803e8a-d6c9-11e2-94b2-28d109f53603.png)