Bug 93287 LTK Core Refactoring triggered on shutdown of JavaPlugin
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/JavaPlugin.java
* Since 3.0 the tab width is managed by the extended texteditor and
		 * uses a new key.
		 */
		store.putValue(oldTabWidthKey, store.getString(newTabWidthKey));
		fPropertyChangeListener= new IPropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent event) {
				if (newTabWidthKey.equals(event.getProperty())) {
					IPreferenceStore prefStore= getPreferenceStore();
					prefStore.putValue(oldTabWidthKey, prefStore.getString(newTabWidthKey));
				}
			}
		};
		store.addPropertyChangeListener(fPropertyChangeListener);
		
		/*
		 * Backward compatibility for the refactoring preference key. 
		 */
 
		
		
		
		
		store.setToDefault(PreferenceConstants.REFACTOR_ERROR_PAGE_SEVERITY_THRESHOLD);
		
		if (!store.getBoolean(JavaDocLocations.PREF_JAVADOCLOCATIONS_MIGRATED)) {
			JavaDocLocations.migrateToClasspathAttributes();
		}
		
		ProfileStore.checkCurrentOptionsVersion();
	}