Bug 299438 [CommonNavigator] CNF viewer state non properly reset when NCEs are activated or deactivated
The map of the objects to the NCEs should be reset whenever the NCEs associated with the viewer to change to avoid having stale label information. This has shown up when looking at the CNF tests that change the viewer.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
*/
	private ViewerComparator sorter;
	/**
	 * This viewer's filters (element type: <code>ViewerFilter</code>).
	 * <code>null</code> means there are no filters.
	 */
	private List filters;
	/**
	 * Indicates whether the viewer should attempt to preserve the selection
	 * across update operations.
	 * 
	 * @see #setSelection(ISelection, boolean)
	 */
	private boolean preserveSelection = true;
	/**
	 * Indicates whether a selection change is in progress on this viewer.
	 * 
	 * @see #setSelection(ISelection, boolean)
	 */
	private boolean inChange;
	
	/**
	 * Used while a selection change is in progress on this viewer to indicates
	 * whether the selection should be restored.
	 * 
	 * @see #setSelection(ISelection, boolean)
	 */
	private boolean restoreSelection;
	/**
	 * List of double-click state listeners (element type: