Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Set version to 2.16.29-SNAPSHOT
  Set version to 2.16.28
  Use JGit 5.1.15.202012011955-r javadoc to resume release build

Change-Id: Ic0deb6c18e8012d6153c38f80b4c999784574d34