Bug 309563 All packages (o.e.e4.ui.model.workbench.edit) of ItemProviders need to be exported
Before, there is only one ApplicationItemProviderAdapterFactory used by e4 Visual Designer. Now with the new model in multiple packages, we need to export all the corresponding ItemProvider.
bundles/org.eclipse.e4.ui.model.workbench.edit/src/org/eclipse/e4/ui/model/application/ui/basic/provider/PartItemProvider.java
* <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	protected void addContextPropertyDescriptor(Object object) {
		itemPropertyDescriptors.add
			(createItemPropertyDescriptor
				(((ComposeableAdapterFactory)adapterFactory).getRootAdapterFactory(),
				 getResourceLocator(),
				 getString("_UI_Context_context_feature"), 
				 getString("_UI_PropertyDescriptor_description", "_UI_Context_context_feature", "_UI_Context_type"), 
				 UiPackageImpl.Literals.CONTEXT__CONTEXT,
				 true,
				 false,
				 false,
				 ItemPropertyDescriptor.GENERIC_VALUE_IMAGE,
				 null,
				 null));
	}
	/**
	 * This adds a property descriptor for the Variables feature.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	protected void addVariablesPropertyDescriptor(Object object) {
		itemPropertyDescriptors.add
			(createItemPropertyDescriptor
				(((ComposeableAdapterFactory)adapterFactory).getRootAdapterFactory(),
				 getResourceLocator(),