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
/**
	 * {@value} (boolean): True indicates the
	 * "Available Extensions" tab in the "Available Customizations" dialog
	 * should not be available for the user (defaults to <b>false</b>).
	 * 
	 */
	String PROP_HIDE_AVAILABLE_EXT_TAB = "org.eclipse.ui.navigator.hideAvailableExtensionsTab"; 
	/**
	 * {@value} (boolean): True
	 * indicates the entire "Available Customizations" dialog should not be