Bug 221521 [Markers] New markers API needs to be pared down
We have too much API in some of the new classes and they can be moved to internals
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
public static final String ALL_MARKERS_GENERATOR = "org.eclipse.ui.ide.allMarkersGenerator"; 
	/**
	 * The id for the new markers view.
	 */
	public static final String MARKERS_ID = "org.eclipse.ui.ide.MarkersView"; 
	private static final String ATTRIBUTE_GENERATOR_ID = "generatorId"; 
	private static MarkerSupportRegistry singleton;
	
	private static Object creationLock = new Object();
	/**
	 * Get the instance of the registry.
	 * 
	 * @return MarkerSupportRegistry
	 */
	public static MarkerSupportRegistry getInstance() {
		if (singleton == null) {
			synchronized (creationLock) {
				if (singleton == null) {
					
					singleton = new MarkerSupportRegistry();
				}
			}
		}
		return singleton;
	}
	private Map registeredFilters = new HashMap();
	private Map markerGroups = new HashMap();
	private HashMap categories = new HashMap();
	private HashMap hierarchyOrders = new HashMap();
	private MarkerType rootType;