-add calendar to detailView
-chang save (download) icon
-add EventKit, basic calendar is working
-calendar event now can be set with information of the selected info session.
-add class variable: + (NSDictionary *) alertIntervalDictionary to infosession.
-calendar event is managed successfully, can sync with calendar
-since data is not saved, after a new start, the event created is forgotten.
-check point:Calendar event adding is implemented!