[OR-693] - Integrate fullcalendar into communities
[OR-696] - Add ical.js to frontend
[OR-695] - Create UI to create a new Event
[OR-700] - Create calendar using dav
[OR-698] - eventmessage directive
[OR-706] - Create the frontend icaljs factory
[OR-707] - Implement caldav service client
Merge pull request #580 in OR/rse from ~PKEWISCH/rse:esn_caldav_integrate3 to master

* commit '434efa100f37f41c2b336451e22c1e91b52c95ed':
  [OR-707] - Implement caldav service client
  [OR-706] - Create the frontend icaljs factory
  [OR-698] - eventmessage directive
  [OR-700] - Create calendar using dav
  [OR-695] - Create UI to create a new Event
  [OR-696] - Add ical.js to frontend
  [OR-693] - Integrate fullcalendar into communities