Merge branch 'stable-2.13' into stable-2.14

* stable-2.13:
  Set version to 2.13.14 and require Java 8
  Set version to 2.13.13
  Release Gerrit version 2.13.12
  Bump to Gerrit v2.13.11 for macOS intaller
  Bump to Gerrit version 2.13.11
  Get Ubuntu 15.04 packages from old-releases
  Bump to Gerrit Ver. 2.13.10
  Bump to Gerrit Ver. 2.13.9

Change-Id: Ie26232f0371a150cf27b1eaba07f64c5d0ccf062