Bug 205049 Other plug-ins should be able to define default content generator
Currently only the content generator can define which plug-ins it can be the default for - we need a way for plug-ins to refer back to the marker support for thier own generator.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
singleton = new MarkerSupportRegistry();
				}
			}
		}
		return singleton;
	}
	private Map registeredFilters = new HashMap();
	private Map markerGroups = new HashMap();
	private Map markerGroupingEntries = new HashMap();
	private HashMap categories = new HashMap();
	private HashMap hierarchyOrders = new HashMap();
	private MarkerType rootType;
	private HashMap generators = new HashMap();
	private HashMap fields = new HashMap();
	/**
	 * Create a new instance of the receiver and read the registry.
	 */
	private MarkerSupportRegistry() {
		IExtensionTracker tracker = PlatformUI.getWorkbench()
				.getExtensionTracker();
		IExtensionPoint point = Platform.getExtensionRegistry()
				.getExtensionPoint(IDEWorkbenchPlugin.IDE_WORKBENCH,
						MARKER_SUPPORT);
		if (point == null) {
			return;
		}
		IExtension[] extensions = point.getExtensions();
		
		Map groupingEntries = new HashMap();
		Set attributeMappings = new HashSet();