Inital ViewPager Support

Support for tab-swiping using a ViewPager
Transitioned tabs from Activities to Fragments (from the support library)
Removed intent passing to tabs as they are now fragments
MyTabListener: ViewPager tab listener class
CardsFragment: Refactoring and restructuring
Some other general code cleanup and improvements, including try-catch
 optimisations.
Moved the commit countdown to start closer to when the request is made.

This merges in the entirity of the merge commit "Merge change timer start with fixes for refreshing when gerrit changes".
This includes both branches for the ViewPager implementation.
Drawable changes have been separated from this change.

Patch Set 2: Fix build

Change-Id: I29ea3e95fc619c3c02e40a7898d271df52eb14f3