GH-376 Re-set NSWindow's delegate just before closing
GH-376 Re-set NSWindow's delegate just before closing

- When exiting full screen, often, some delegate methods of NSWindow get called after deallocation. This is just a quick-and-dirty fix.

qvacua/vimr,qvacua/vimr,qvacua/vimr,qvacua/vimr,qvacua/vimr