INFRSTR-255 migrated from https://source.sakaiproject.org/contrib/external-calendaring-service (see contrib repo for svn log history)

git-svn-id: https://source.sakaiproject.org/svn/external-calendaring-service/branches/external-calendaring-service-1.0.x@284956 66ffb92e-73f9-0310-93c1-f5514f145a0a