Bug 207268 Add visibility option for plot within axes
For chart with axes, we should make plot within axes invisible. Meantime, other plots, such as axes, legend and title, should be visible. This enhancement doesn't include UI change, and it is required for cross tab integration.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/layout/LayoutPackage.java
/**
	 * The feature id for the '<em><b>Min Size</b></em>' containment reference.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	int LABEL_BLOCK__MIN_SIZE = BLOCK__MIN_SIZE;
	/**
	 * The feature id for the '<em><b>Outline</b></em>' containment reference.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	int LABEL_BLOCK__OUTLINE = BLOCK__OUTLINE;
	/**
	 * The feature id for the '<em><b>Background</b></em>' containment reference.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	int LABEL_BLOCK__BACKGROUND = BLOCK__BACKGROUND;
	/**
	 * The feature id for the '<em><b>Visible</b></em>' attribute. <!--
	 * begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @generated
	 * @ordered
	 */
	int LABEL_BLOCK__VISIBLE = BLOCK__VISIBLE;
	/**