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
* Set the font.
		 * @param font 
		 */
		public void setFont(Font font) {
			this.font = font;
		}
		/**
		 * Set the foreground color.
		 * @param foreground
		 */
		public void setForeground(Color foreground) {
			this.foreground = foreground;
		}
	
		
	}
	/**
	 * The safe runnable used to update an item.
	 */
	class UpdateItemSafeRunnable extends SafeRunnable {
		private Widget widget;
		private Object element;
		private boolean fullMap;
		UpdateItemSafeRunnable(Widget widget, Object element, boolean fullMap) {
			this.widget = widget;
			this.element = element;
			this.fullMap = fullMap;
		}
		public void run() {
			doUpdateItem(widget, element, fullMap);