Factor tcpSlaveAgentListener logic to a single method able to shutdown
existing listener if required, then launch a new one if it needs to.

Also, the administrative monitor gets cleared if we had previously a
taken port and changed to a valid port.

few chances there’s another implementation
but if one exists Function.isWindows would probably be wrong implementation

Avoid "EmptyStackException: null" in Items#getCanonicalName

Make it easier to determine Computer is Unix or Windows

[JENKINS-26147] New home for BUILD_NOW_TEXT

Deleting bogus class ExceptionInterruption

This reverts commit 68b383e0.

Reduce logging level

Null safety for hudson.model.Result

Use log4j-bridge of slf4j and dont ship log4j.

- 252e1296 doesn't work for all cases as there are code paths
  where a pending launch can be removed from the pending list and not have spent() called.
- There was no reason for iterating the list twice anyway, as all of this takes place with the locks held
- My notifying each one as we process, if there is an Error, we will not leave any stranded. The next run
  through, if there is one, will cover those instances.

... as a control case in the master branch to ensure the changes in the
config-ui-changes do not break its behaviour.

- They have been removed from the pendingLaunches, so once we leave this method we have no reference to them
- Arguably the call to spent should take place when removing from the pendingLaunches, but that would change
  the method contract

Fix typo

Don't run trigger for disabled/copied projects

[FIXED JENKINS-28844] The curious case of the Channel memory cycles