Added background, app icon, buttons.

UI Improvements:
* Added blue background
* Set app icon
* Changed buttonlayout
* Changed font color

TODO:
* Change font color in ContactsActivity and TimeActivity.

This is based on vinaykola's fork, so discard non-UI changes in any files changed, since you've made some changes.
I don't think you should do an automatic merge, it might revert some of the changes you made.