Bug 188829 Move the item ,the trans of the model don't close.
1:New report design. 2:Add a Embedded image. 3:Add another imge , then drag the second imge to the first position. 4:Change the size of the first image. Expected: Image change the size. Now: Image size don't change.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentElementCommand.java
*/
	protected void addItem( MemberRef ref, Object value )
			throws SemanticException
	{
		ActivityStack stack = getActivityStack( );
		stack.startTrans( ModelMessages
				.getMessage( MessageConstants.ADD_ITEM_MESSAGE ),
				getTransOption( ) );
		
		DesignElement tmpElement = copyTopCompositeValue( );
		List list = null;
		PropertyDefn propDefn = ref.getPropDefn( );
		list = (List) tmpElement.getLocalProperty( module,
				(ElementPropertyDefn) propDefn );
		PropertyListRecord record = new PropertyListRecord( tmpElement,
				new CachedMemberRef( ref, list.size( ) ), list, value );
		stack.execute( record );
		record.setEventTarget( eventTarget );
		stack.commit( );
	}
	/**
	 * @param ref
	 * @param value
	 * @throws SemanticException
	 */
	protected void removeItem( MemberRef ref ) throws SemanticException
	{
		ActivityStack stack = getActivityStack( );
		stack.startTrans( ModelMessages
				.getMessage( MessageConstants.REMOVE_ITEM_MESSAGE ),