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.

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.

* commit 'c628bdd3':
  First pass at a fix for JENKINS-8592.

(recording the previous commit 9d7d0d75 by Richie Vos)

The problem is that the sending side has no way of knowing when the
receiving side has hung up. So when the receiving side hangs up we should
be able to read till the stream runs out, then close. Not the optimal
solution, but one that should work for now.

http://issues.jenkins-ci.org/browse/JENKINS-8592

HUDSON-8401.

This grouping of tests targets all Sunday to *another day of week* cron
tabs. There are likely other pairs that could be tested, but this seemed to
work out most of the bugs.

After thinking about it, I don't want to deal with hudsonslave here. jenkinsslave should be found anyway, so that code path should not have been triggered.
And cleaning up residual services isn't jenkins job. Otherwise both can't coexist.

After thinking about it, I don't want to deal with hudsonslave here. jenkinsslave should be found anyway, so that code path should not have been triggered.
And cleaning up residual services isn't jenkins job. Otherwise both can't coexist.

JENKINS-8698 HudsonTestCase sometimes fails with NPE in tearDown() while trying to free htmlunit resources

Not really sure what is happening, but I don't think the build should fail here.
So let's try to be more resiliant (try twice loading the page) and don't fail if the exception occurs again.

Persist a user-requested offline status for a slave across
restarts. Previously slaves would come back online if the server
was restarted while they were marked 'temporarily offline'.

I believe this also addresses JENKINS-7934 and JENKINS-7805
which look like duplicates.

add "since 1.378" in one changelog item

Some more work:
* reviewed some callers
* took note that some classes have been moved into stapler
* used IOUtil.closeQuietly() in a few places