Implement de/serialization and provide examples

[fcheadle]

At the very minimum, the example game needs to save and load itself. This could be as simple as calling the appropriate methods, although its possible it will require some specific tomfoolery.

This should include a Save/Load function in the example game.

[Chris3606]

This may be exceptionally difficult to implement sensibly until GoRogue finishes its serialization support: GoRogue#190.