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
- Reordered a few things in Interface settings
- Cleaned up and reordered a few strings
- Clean up in AndroidManifest.xml
- Resized hdpi ic_settings_about_carbon.png