Fixed crashing bugs related to changing views too quickly, and closing behaviour. Parent window now responsible to close the window by listening out for kNotifPreferenceWindowDidClose
Now Preference VC supports initialFirstResponder, which allows the key view loop to be defined instead of the search for non-buttons method
Fixed bug where selecting toolbar item via keyboard doesn't select it
Made it appear in the middle, and made default size of preference window same as Due's
Fixed warnings about XIB file position
Made window non-restorable