[maven-release-plugin] prepare release calendar-2.9.1

git-svn-id: https://source.sakaiproject.org/svn/calendar/branches/calendar-2.9.x@119750 66ffb92e-73f9-0310-93c1-f5514f145a0a
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://source.sakaiproject.org/svn/calendar/branches/calendar-2.9.x@119752 66ffb92e-73f9-0310-93c1-f5514f145a0a
Jenkins post-build: Auto-updating master version to 2.9-SNAPSHOT for next release http://builds.sakaiproject.org:8080/job/calendar%202.9.x/

git-svn-id: https://source.sakaiproject.org/svn/calendar/branches/calendar-2.9.x@119753 66ffb92e-73f9-0310-93c1-f5514f145a0a