Show commit details

This is the start of showing commit details 

Todo:

- [x] style everything
- [ ] line numbers for diffs
- [ ] highlight additions/deletions of diffs

This will close #111 

---

Current status:

![github_notifications](https://cloud.githubusercontent.com/assets/173/3883692/72774f7a-21a4-11e4-9eb3-f8bf82199272.png)

---

Page this is replicating:

![update_test_org__679c1db__bkeepers_test](https://cloud.githubusercontent.com/assets/173/3863875/700075fc-1f4f-11e4-96e6-a9a2867dff9d.png)