Bug 198971 [CommonNavigator] Provide extension schema for setting help ID
I haven't been able to find a way to set the help ID for a view using the common resource navigator. It seems that having schema support for this would be the best way to handle this.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorViewerDescriptor.java
static final String ATT_PATTERN = "pattern"; 
	private static final String TAG_CONTENT_EXTENSION = "contentExtension"; 
	private static final String TAG_ACTION_EXTENSION = "actionExtension";  
	private final String viewerId;
	private String popupMenuId = null;
	private Binding actionBinding = new Binding(TAG_ACTION_EXTENSION);
	private Binding contentBinding = new Binding(TAG_CONTENT_EXTENSION);
	private MenuInsertionPoint[] customInsertionPoints = null;
	private boolean allowsPlatformContributions = true;
	private String inheritBindingsFromViewer;
	
	private final Properties properties = new Properties();
	private Set dragAssistants; 
	/**
	 * Creates a new content descriptor from a configuration element.
	 * 
	 * @param aViewerId
	 *            The identifier for this descriptor.
	 */
	NavigatorViewerDescriptor(String aViewerId) {
		super();
		this.viewerId = aViewerId;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.navigator.extensions.INavigatorViewerDescriptor#getViewerId()
	 */
	public String getViewerId() {
		return viewerId;