Settings menu cleanup

- Superuser header moved below Developer Options
- Having two performance options makes the menu clunky. So I took out
the CM one as the AOKP one offers more functionality over CM's one
- Moved toolbar settings to System

Compiled and works fine for me, looks much less cluttered as well.
![Screenshot1](https://f.cloud.github.com/assets/1753736/295776/03adceb8-94b3-11e2-9366-f5db33658e3e.png)
![Screenshot2](https://f.cloud.github.com/assets/1753736/295777/03c4776c-94b3-11e2-860b-821d52ea3a64.png)