[maven-release-plugin] prepare release git-2.2.9
[maven-release-plugin] prepare for next development iteration
Update to git-client-plugin 1.12.0 [JENKINS-25639]

Revision.equals() needed to complete the fix of JENKINS-25639
Update to mockito 1.10.13
Update to JGit 3.5.2 to match git-client-plugin 1.12.0
DefaultBuildChooser.getCandidateRevisions() now returns Set<Revision> to filter duplicates.
[FIXED JENKINS-25639]
test DefaultBuildChooser with unknown SHA1
[Fix JENKINS-22536] Use ISO 8601 date format for GitChangeSet dates

The date format presented previously was a combination of the ISO 8601
formatted date and a copy of the time zone information from the original
git change log entry.

The new format is only the ISO 8601 formatted date, since it already
includes time zone information.