Support iCal file import and export
Support import/export of iCalendar files.
Due to QtOrganizer limitation, we can't import/export Location and Attendees fields, as a work around we use a third party ical js library to handle both fields.
On Import view:
Import Error:
Import Error: No events found:
On Calendar Option view:
Export Popup
Individual event: add "Share" button
fixes #179
contribute to #115
Edited by Lionel Duboeuf