[maven-release-plugin] prepare release mailsender-1.7.3

git-svn-id: https://source.sakaiproject.org/svn/mailsender/branches/1.7@125226 66ffb92e-73f9-0310-93c1-f5514f145a0a
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://source.sakaiproject.org/svn/mailsender/branches/1.7@125228 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/mailsender%201.7.x/

git-svn-id: https://source.sakaiproject.org/svn/mailsender/branches/1.7@125229 66ffb92e-73f9-0310-93c1-f5514f145a0a