Bug 130182 [CommonNavigator][Help] missing help in Customize View dialog
open the Filters... dialog and click the help button, note no help appears.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/INavigatorViewerDescriptor.java
* content extension is 'visible' if it matches a viewerContentBinding for
	 * the given viewer id.
	 * 
	 * @param aContentExtensionId
	 *            The id to query
	 * @return True if the content extension matches a viewerContentBinding for
	 *         the viewer id of this descriptor.
	 */
	boolean isVisibleContentExtension(String aContentExtensionId);
	/**
	 * Returns true if the action extension of the given id is 'visible'. An
	 * action extension is 'visible' if it matches a viewerActionBinding for the
	 * given viewer id.
	 * 
	 * @param anActionExtensionId
	 *            The id to query
	 * @return True if the action extension matches a viewerActionBinding for
	 *         the viewer id of this descriptor.
	 */
	boolean isVisibleActionExtension(String anActionExtensionId);
	/**
	 * Returns true if the content extension of the given id matches a
	 * viewerContentBinding extension that declares isRoot as true.
	 * 
	 * @param aContentExtensionId
	 *            The id to query
	 * @return True if the content extension matches a viewerContentBinding
	 *         which declares 'isRoot' as true for the viewer id of this
	 *         descriptor.
	 */