RenderSceneArgs now accepts a full visible extend.

However, it is handled (and used) as not rotated one for now.
Import static trigonometric directly.
Implement transformBallroomToPixel() using the other one.
Bumped used JUnit.
Added methods to rotate the point against an origin.
Java doc header for the point class.
Added toString() method to the Point class.
Import assertEquals() statically.
Added a simple add() method to the Point class.
Added distance() method.
Added center() method.
Introduced prelimiary support for view rotation.

It is not perfect yet and has some minor glichtes due to our relative
discrete handling of points.
Make the rotation accessible for users via simple menu entries.
Merge branch 'ballroom-rotation-support'

This adds primitive support for rotating the view. Currently, it is
only accessible via menu entries (and the corresponding short cuts).