Refactor some code (details inside)

* The first commit, 5886f7b691346508ff56d, cleans up the ``StageDialog``, ``StageListener`` and ``StageActivity``. A few things are now a bit clearer, for example ``pauseOrContinue()`` was replaced by ``pause()`` and ``resume()``.

* The second commit, a78daed39683db5c320a2bd, cleans up the ``ScriptActivity`` a bit. Probably the biggest change in my opinion was the renaming of the method ``setHoveringBrick()`` to ``animateHoveringBrick()``. It didn't *set* much, and even returned a ``boolean``. Not something I'd expect from a setter.

* The third commit, 85eeac047fe0cbc4f471e4c2f79d8416f3565b77, simply moves the Fragment tests to their own package, to reflect the package names of the actual project.

* The fourth commit, 3619c8154b1a259b7358b5f0db2e16c40698de89, renames a few variables here and there and refactors some very minor parts of the code. The biggest change here is the introduction of a new class called ``BottomBar``. This class is supposed to be helper class for dealing with the various aspects of the bottom bar. The idea behind it was to not have everything in the ``Utils`` class, but have some individual helper classes where needed. Think about the ``Toast`` class which provides static methods to create and show ``Toast``s. This change is up for debate as well as the location of the class.

* The fifth and last commit, cbdbced0b4714c67c815fcd3fbe94a5110dca365, deletes an unused .xml file and brings back source code browsing for the libgdx functions. Please see [this link](http://stackoverflow.com/a/11579339/1928168) for more details. I was unable to do the same thing for the Robotium Javadoc, but that doesn't mean it's not possible.

Neither of these changes are absolutely necessary, so I'd welcome a review and feedback.
[Successful testrun](http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test/313/)