Merge branch 'stable-2.16' into stable-3.0

* stable-2.16:
  Set version to 2.15.23-SNAPSHOT
  Set version to 2.16.27-SNAPSHOT
  Set version to 2.16.26
  Set version to 2.15.22
  Avoid creating HTTP Sessions for Git-over-HTTP
  Avoid creating HTTP Sessions for Git-over-HTTP

Change-Id: Iaca3d95a1e394b96202ea46948bea62834ca977f