Massive UI clean up
- Clean up closure function.
- Fix problem with drag drop and buttons.
- Fix draggable elements (match the official UI).
- Fix guild markers on minimap.
- Fix possible memory leak (keydown could be set multiple times).
- Fix trade UI, conclude button should be enabled just when the two players validated the trade.
- Trying to fix the Firefox mouse intersection bug (mouseleave + remove problem, test case: http://jsfiddle.net/7h4sj/)
- Fix possible problem with resizing UI.