Bug 123207 PropertyHandle items cannot be moved down
Use the property handle to move down the item. It seems not work.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/activity/AbstractElementCommand.java
{
	/**
	 * The element to modify.
	 */
	protected DesignElement element = null;
	/**
	 * Constructor.
	 * 
	 * @param module
	 *            the module
	 * @param obj
	 *            the element to modify
	 */
	public AbstractElementCommand( Module module, DesignElement obj )
	{
		super( module );
		assert obj != null;
		element = obj;
	}
	/**
	 * Checks and adjusts the new position.
	 * 
	 * @param oldPosn