Changed levels to support the ISokobanLevel functionality
New interface, used to retrieve data from every level automatically
Handler for the ISokobanLevel interface, in here every level is registered (and only here).
Levelbounds are now retrieved from the ISokobanLevel implementations, instead of a switch case.
Changed the level conversion so it correctly implements the ISokobanLevel interface.
The level converter now looks for signs which display level difficulty, number, and name.
Removed the list of level names, as they are now stored in the level itself.
Changed to support the ISokobanLevel interface.
Version control, and support for the new interface.
Removed the getting of the levelbounds.
Removed the list of generate() invokes.