Huge Settings Mega Ka... Revamp!

- New CarbonRom settings header
- New Xposed settings header
- Reworked main Settings menu. It now lists CarbonRom, Performance, Themes
  and Xposed headers under Carbon Links
- Moved About Carbon to new CarbonRom settings
- Moved Pie Controls to its own settings submenu (thanks PA for the icon)
- Moar clean up everywhere else