Bug 117149 Add additional datapoint markers
I would like to propose adding additional datapoint markers. Attached is a set of markers I would like supported.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/attribute/impl/MarkerImpl.java
* @ordered
	 */
	protected boolean visible = VISIBLE_EDEFAULT;
	/**
	 * This is true if the Visible attribute has been set.
	 * <!-- begin-user-doc
	 * --> <!-- end-user-doc -->
	 * @generated
	 * @ordered
	 */
	protected boolean visibleESet = false;
	/**
	 * The cached value of the '{@link #getIconPalette() <em>Icon Palette</em>}' containment reference.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @see #getIconPalette()
	 * @generated
	 * @ordered
	 */
	protected Palette iconPalette = null;
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	protected MarkerImpl( )
	{
		super( );
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->