[Android] Simplify how ListActivities set their adapters. Since they are ListActivities, there is an underlying method for setting the adapters (setListAdapter()), so now we can remove calls that get the ListView object, since we don't need to directly access them now.
[Android] Use accessors with FileWrapper.java. Maintains encapsulation. Also make FileWrapper.java implement Comparable, since it already implements compareTo.
[Android] Fix variable accessibility within BackStackItem. These aren't used outside of the class, so they should be made private.
Merge pull request #332 from lioncash/master

[Android] Simplify how ListActivities set their adapters. Also tiny FileWrapper change.