BUG Fieldgroup styling

Before:
![fieldgroup_before_styling](https://f.cloud.github.com/assets/1517053/868286/47ec0f8a-f78d-11e2-9d09-0e59beac1b57.png)
![sitetree_before_styling](https://f.cloud.github.com/assets/1517053/868287/48043d62-f78d-11e2-817e-aff0f9e30395.png)

After:
![sitetree_after_styling](https://f.cloud.github.com/assets/1517053/868290/4c29481a-f78d-11e2-83cb-a2f449d0839a.png)
![fieldgroup_after_styling](https://f.cloud.github.com/assets/1517053/868289/4c332f24-f78d-11e2-98e8-6ad88d9eb061.png)