Bug 53839 new search: remember the sort options
I20040302 the group-by capabilties and the buttons are great. So good that I would want the group-by setting to be remembered across sessions.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/JavaPlugin.java
* pre-3.0 plug-in to the new preference key. This is done only once.
		 */
		final String oldTabWidthKey= PreferenceConstants.EDITOR_TAB_WIDTH;
		final String newTabWidthKey= ExtendedTextEditorPreferenceConstants.EDITOR_TAB_WIDTH;
		String tabWidthPropagatedKey= "tabWidthPropagated"; 
		if (getPreferenceStore().contains(oldTabWidthKey) && !getPreferenceStore().isDefault(oldTabWidthKey)) {
			if (!getPreferenceStore().getBoolean(tabWidthPropagatedKey))
				getPreferenceStore().setValue(newTabWidthKey, getPreferenceStore().getInt(oldTabWidthKey));
		}
		getPreferenceStore().setValue(tabWidthPropagatedKey, true);
		/*
		 * Backwards compatibility: set the Java editor tab width in this plug-in's
		 * preference store with the old key to let older versions access it.
		 * Since 3.0 the tab width is managed by the extended texteditor and
		 * uses a new key.
		 */
		getPreferenceStore().putValue(oldTabWidthKey, getPreferenceStore().getString(newTabWidthKey));
		fPropertyChangeListener= new IPropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent event) {
				if (newTabWidthKey.equals(event.getProperty()))
					getPreferenceStore().putValue(oldTabWidthKey, getPreferenceStore().getString(newTabWidthKey));
			}
		};
		getPreferenceStore().addPropertyChangeListener(fPropertyChangeListener);
	}
	
	/**
	 * Uninstalls backwards compatibility for the preference store.
	 */
	private void uninstallPreferenceStoreBackwardsCompatibility() {