Bug 214648 [Markers] AttributeMarkerGroupings and GroupingEntries not being cleaned up on removal
We are still leaving the references to AttributeMarkerGroupings and GroupingEntries when we unload
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerGroup.java
MarkerGroup markerGroup;
		GroupMarkerField(MarkerGroup group) {
			markerGroup = group;
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.ui.internal.provisional.views.markers.api.MarkerField#getValue(org.eclipse.ui.internal.provisional.views.markers.api.MarkerItem)
		 */
		public String getValue(MarkerItem item) {
			if (item.getMarker() != null) {
				try {