2013/06/28: IGAS v40
    1. Improve the System.Widget.Unit.IFResurrect, make sure its objects will be hidden when the resurrection is over
    2. Fix the System.Widget.Unit.LevelLabel, refresh when the LevelFormat is changed

2013/06/27: IGAS v39
    1. Delete the custom event system from System.Object.
    2. Keyword 'script' is renamed to 'event'.
    3. Update all files with those changes.