Laenion

The following commits contain several fixes to compile and play the game on other systems than Ubuntu and to fix segmentation faults caused by the threading implementation. All changes have been compile- and run-tested on both Ubuntu 12.04 and Slackware64 current.

This pull request already contains the new fullscreen implementation - I haven't changed anything since my last mail (i.e. not cleaned up the window initialization), but at least it has more features (fullscreen, minimization) than the current implementation ;-)