* JENKINS-8670:
  [FIXED JENKINS-8670] recording the fix
  Added support to MavenBuild for alternateSettings

JENKINS-8670

Note that the above description is incorrect as to what the merge was about.
It is the message that I intended to make. It appears that I accidentaly merged multiple fixes waiting to be reviewed on my private fork.

This reverts commit dce0d2af, reversing
changes made to 63f67f30.

Classes that derive from FederatedIdentity are put into the session and should therefore be serializable

hudson.UDPBroadcastThread#testMulticast hangs when the network isn't enabled on my Linux box: joinGroup throws IOException and the ready lock isn't released.
This ready lock is only used in the tests.

It is slow and take 10sec on my compiter. Disabling it. One could remove it I guess.

JENKINS-8702 improve unit tests. UpdateCenterTest depends on online resource and takes too long. Fix this

Looks like I broke this in d88df7ea

Reapplied 329a0201

Conflicts:
	core/src/main/java/hudson/widgets/HistoryWidget.java

* JENKINS-4756:
  minor touch up
  FIXED JENKINS-4756 the executor number was not always unique. Computer.executors.size() does not provide a unique number within one Computer.

* JENKINS-8660:
  fail more gracefully if the header is not provided.
  JENKINS-8660: loading the build history cause an NPE on the History Widget

Yes, this is HUDSON-8656 and not JENKINS-8656.