Merge branch 'master' into extensionlist-listener

* master: (61 commits)
  [JENKINS-28384] Noting merge of #1700.
  update changelog: PR 1682 -> issue 28233, fix markup issue
  Remove duplicated 1.613 section from changelog
  [FIXED JENKINS-28384] NPE when Node.toComputer → null.
  Refactor fingerprint classes: Javadoc and annotations
  fixup ce747f94
  Refactor ArgumentListBuilder#toWindowsCommand
  Improve ArgumentListBuilder#toWindowsCommand test coverage
  Forgotten @test annotation
  updated changelog for release
  updated changelog for release
  [maven-release-plugin] prepare release jenkins-1.613
  [maven-release-plugin] prepare for next development iteration
  Report launcher exited before establishing the channel
  Remove erroneous '+ ' from log message.
  Increase visibility of Java 7 requirement
  Expose SlaveComputer#getLogDir() explicitly
  [FIXED JENKINS-28227] Switch to Enblish locale in RunTest#getDurationString to test messages.
  Noting #1591
  Noting #1682
  ...