Merge branch 'stable-2.14' into stable-2.15

* stable-2.14:
  Set Gerrit to 2.14.20
  Set version to 2.13.14 and require Java 8
  Set version to 2.13.13
  Set Gerrit to 2.14.19

Change-Id: I9862ffed803377346cb7da44f29b4d90bd8f2651