After a few months where Kolf-NG was just a quite complex rendering engine for simple geometric objects, I thought that it is time to make it a game.

As I was without internet connection last week, and SVN does not allow offline commits, here is everything at once.

Let's start with the new classes:
* The Kolf::HoleObject completes the set of base elements.
* The Kolf::Player records scores. (Currently, only local players are supported.)
* The Kolf::Game class manages players, putting control, and so on.
* The Kolf::ScoreCard shows the scores which it gathers from the Game class.
* The Kolf::EmptyOverlay closes the gaps in overlay support.
Additionally, improvements and additions all over the code include:
* disable the squared format of the 2D view temporarily (it does not work correctly, either)
* a second hole for the test course (created with KWrite as there is still no un-inconvienent editor in Kolf)
* a simple garbage collection in the 2D view for objects on its scene
* some Kolf::Object methods made purely virtual
* added a kolf-ng.desktop file