statistics window, game window

[DanielBruegmann]

The statistics window should not cover part of the game view. The game window should have the focus so escape closes the terminates, without having to click in the game view first. It might be easier to make sure that the game view is always on top and not worry about the overlap for now. Maybe should be only one window at some point in the future. Would it be possible to show the statistics in the fullscreen mode and do we want this?

[DanielBruegmann]

This commit solves the problem with keyboard input for me (the game window has the focus) and causes the game window to be on top. Moving to Optional.

[PascalCremer]

We should do some refactoring here. Now there is no reason why StatisticsView should implement runnable. But lets discuss it first. Is there some reason why we would like the windows to run in a thread? One could think of buggy AIs which have endless loops causing Keyboard input not to be processed anymore. But since we want to run the AIs in parallel as a long term goal, the graphics can run in the main loop.

[PascalCremer]

One can also consider putting both frames in one window.