updated for retina display

[whacked753]

Hi guys, I tried your game on a platform Apple MacBook.
the problem is that the game from error when setting a resolution suitable for retina display.
I have no idea if this is the right section to recommend an update regarding this problem.
I hope I have helped to give my feedback.
Byee ^^

[Tobbi]

Unfortunately, I don't have a retina display to test, but could you possibly start supertux with ./supertux2 --debug and see if there are any debug messages related to this on the console?

Thanks in advance!

--Tobbi