OSX full screen strategy full screen listener never removed

[caprica]

Needs a brief review.

We could implement a release() method on video surface, but it seems somewhat overkill since it is only this one instance for the OSX strategy that would benefit from it.

Since this issue relates to clean-up anyway, there seems little point as the Window we're listening to is going to be disposed anyway, and then the JVM is about to exit in most cases.

I don't think we need to do anything, but documenting this issue in case.

[caprica]

It's simply not worth making significant changes for this edge case. Once the JVM goes away so does the listener, so there's no real point.

[caprica]

#924