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.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/StructuredViewerManager.java
* @return the object
	 */
	public Object getData(Object element) {
		synchronized (viewerDataMap) {
			return viewerDataMap.get(element);
		}
	}
	/**
	 * 
	 * @param aViewer
	 * @param contentService 
	 */
	public StructuredViewerManager(StructuredViewer aViewer, NavigatorContentService contentService) {
		super();
		viewer = aViewer;
		viewerDataMap = new HashMap();
		StructuredViewerAccess.hookAssociateListener(viewer, viewerDataMap, contentService);
	}
	/**
	 * 
	 * @return The real viewer.
	 */
	public Viewer getViewer() {
		return viewer;
	}
	/**
	 * 
	 * @param anOldInput
	 * @param aNewInput
	 */