add department detail page and nested shift grids

### What is the problem / feature ?

There was no department detail page.

fixes #33 

### How did it get fixed / implemented ?

- Added a list view and a detail view for departments.
- The department detail view has the entire shift grid for that department's shifts nested in it.
- Also added a shift grid to the users profile page if they have any shifts registered.

### How can someone test / see it ?

- Visit the departments top nav item.
- Claim a shift and then view your profile.

*Here is a cute baby animal picture for your troubles...*

![bear_cub](https://cloud.githubusercontent.com/assets/824194/2557361/d891853e-b6fe-11e3-8fbc-0097b1b394d3.jpg)