Made several changes (see list below)

- Changed theme to Halo Light
- Changed action bar theme
- Made several dozen string changes
- Added Maintainers/Conributors/Social tabs
- Added support for avatars for tabs (maintainers/contributors)
- Link them to correct profiles/google+ pages
- Added Google+, Twitter and Github links in Social tab
- Removed unnecessary images and moved all images to nodpi folder
- Created images for necessary avatars, etc
- Clean up a bit