Bug 233285 [TabbedProperties] Adopt API tooling
The tabbed properties plug-in is still not API tooling enabled.
bundles/org.eclipse.ui.views.properties.tabbed/src/org/eclipse/ui/views/properties/tabbed/TabbedPropertySheetPage.java
* aboutToBeHidden
		 */
		if (currentTab != null) {
			currentTab.aboutToBeHidden();
			currentTab = null;
		}
		disposeTabs(descriptorToTab.values());
		descriptorToTab = new HashMap();
		/**
		 * Remove the label provider change listener.
		 */
		if (hasTitleBar && registry != null) {
			registry.getLabelProvider().removeListener(this);
		}
		if (selectionContributor != null) {
			/**
			 * remove the selection contributed registry.
			 */
			TabbedPropertyRegistryFactory.getInstance().disposeRegistry(
				selectionContributor);
			selectionContributor = null;
		}
	}
	/**
	 * @see org.eclipse.ui.part.IPage#dispose()
	 */
	public void dispose() {
		disposeContributor();
		if (widgetFactory != null) {
			widgetFactory.dispose();