Reworked fragment backstack implementation, up caret now appears on
fragments added to back stack. All backstack fragment logic is now done
in the MainActivity, in onBackPressed().
Removed remaining bugs from SwipeToDismiss (go ahead, try to break it).
Shadow/accessibility still needs some work, but touch events are solid.
Tab bar hides if the user is not on the main fragment.
Merge branch 'master' of https://github.com/BrennaBlackwell/spARK.git

Conflicts:
	spARK/bin/spARK.apk
	spARK/src/edu/uark/spARK/NewsFeedArrayAdapter.java