Adds the item to the scene and redraws the item.
        
        :param      item | <QGraphicsItem>

def addItem( self, item ):
        """
        Adds the item to the scene and redraws the item.
        
        :param      item | <QGraphicsItem>
        """
        result = super(XCalendarScene, self).addItem(item)
        
        if ( isinstance(item, XCalendarItem) ):
            item.rebuild()
        
        return result