title: Fullcalendar refetch events callback
body: <p>Currently using fullcalendar.io</p>
  
  <p>In the documentation, it has calendar.fullCalendar('refetchEvents') that refetch all the events from the server.</p>
  
  <p>In short, I want calendar.fullCalendar('refetchEvents') request to be completed and send me back a callback to let me know. I want all the events to be downloaded before i proceed with certain tasks.</p>
  
  <p>How can i do that?</p>