[JENKINS-27748] Improve exception management in RunMap#retrieve

[FIXED JENKINS-28437] - Do not follow href after sending POST via l:task

[FIXED JENKINS-27939] - DefaultJnlpSlaveReceiver should return true when rejecting a takeover.

* 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
  ...

Simple `<l:task post="true" href="someurl"/>` triggers post request as expected
but then proceeds to href as normal link to. If the URL accepts GET then request
is sent twice it if does not after POSTing on background user get
'POST is required' error.

Refactor Fingerprint classes: Javadoc and annotations

[JENKINS-28384] NPE when Node.toComputer → null

[FIXED JENKINS-28227] Switch to Enblish locale in RunTest#getDurationString to test messages.

Improve ArgumentListBuilder#toWindowsCommand test coverage

Report launcher exited before establishing the channel

Remove erroneous '+ ' from log message.

Remove logs after deleting the computer