Support VisualBoyAdvance

[Zabuzard]

Currently, the game is emulated with a Java-emulator. This makes integration fairly easy, but it is also quite limitting.

Ideally, the project should be able to support a more advanced and industry-standard emulator, such as VisualBoyAdvance.

The problem is that this emulator does not expose any interface to Java. So we would need to implement arbitrary screen capture and forward input events as actual OS-level input. Doable, but not trivial.