User prefrence: align all control groups on top. And some padding for category.

Before:
![screenshot 2014-05-18 16 41 35](https://cloud.githubusercontent.com/assets/297343/3007063/451453e0-de68-11e3-9f7f-e11d732e8c1c.png)
&
![screenshot 2014-05-18 16 41 40](https://cloud.githubusercontent.com/assets/297343/3007064/4553ec12-de68-11e3-9baf-02f57210f5b2.png)
----
After:
![screenshot 2014-05-18 16 30 07](https://cloud.githubusercontent.com/assets/297343/3007053/62df2ea0-de67-11e3-8b96-6172dc236fe6.png)
&
![screenshot 2014-05-18 16 29 58](https://cloud.githubusercontent.com/assets/297343/3007052/62dca356-de67-11e3-8f54-23b6b444bdbc.png)