Added a callback to week number containers (.fc-week-number) in month view. The callback is called weekClick() and can be set using the option weekClick: function(){}.
The callback function takes the arguments weekClick(week, ev, view). No default behaviour is defined. If the weekClick option is not set, the event is ignored.
  week: Week container (.fc-week) of the clicked week number
  ev: Native JS event object
  view: FullCalendar View object