fix Popover closing inside Shadow DOM
fix Popover closing inside Shadow DOM

arshaw/fullcalendar,arshaw/fullcalendar,fullcalendar/fullcalendar,fullcalendar/fullcalendar,fullcalendar/fullcalendar,arshaw/fullcalendar,fullcalendar/fullcalendar,arshaw/fullcalendar