[JENKINS-22326] Calling into foreign code from a toString method, like Queue.Item.getWhy → QueueTaskDispatcher, is unsafe.

java.lang.NullPointerException
	at hudson.model.Job.getBuildDir(Job.java:790)
	at hudson.model.Run.getRootDir(Run.java:993)
	at hudson.model.Run.getLogFile(Run.java:1306)
	at hudson.model.Run.execute(Run.java:1664)
	at hudson.maven.MavenBuild.access$900(MavenBuild.java:94)
	at hudson.maven.MavenBuild$ProxyImpl2.close(MavenBuild.java:636)
	at hudson.maven.AbstractMavenBuilder.end(AbstractMavenBuilder.java:106)
	at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.doRun(MavenModuleSetBuild.java:839)
	at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:523)
	at hudson.model.Run.execute(Run.java:1688)
	at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:519)
	at hudson.model.ResourceController.execute(ResourceController.java:88)
	at hudson.model.Executor.run(Executor.java:231)
java.lang.NullPointerException
	at hudson.model.BuildStepListener.all(BuildStepListener.java:31)
	at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:739)
	at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:714)
	at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.cleanUp(MavenModuleSetBuild.java:1054)
	at hudson.model.Run.execute(Run.java:1733)
	at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:519)
	at hudson.model.ResourceController.execute(ResourceController.java:88)
	at hudson.model.Executor.run(Executor.java:231)

From a random failure of BuildTriggerTest.testMavenBuildTrigger:
java.lang.AssertionError
	at hudson.model.Run.setResult(Run.java:425)
	at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:722)
	at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.cleanUp(MavenModuleSetBuild.java:1054)
	at hudson.model.Run.execute(Run.java:1733)
	at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:519)
	at hudson.model.ResourceController.execute(ResourceController.java:88)
	at hudson.model.Executor.run(Executor.java:231)

Since downloading tool metadata seems inessential for the test, leaving it disabled as is the default.
503 Service Unavailable for http://mirrors.jenkins-ci.org/updates/updates/hudson.tasks.Ant.AntInstaller.json?id=hudson.tasks.Ant.AntInstaller&version=1.557-SNAPSHOT%2520(private-03%252F24%252F2014%252014%253A15%2520GMT-jenkins)

[FIXED JENKINS-19976] Merged #1054: fix class loading from dynamically installed optional dependencies.

[FIXED JENKINS-19544] When OldDataMonitor is reported a Run, just remember the ID rather than holding a strong reference.

[JENKINS-19544] Whether or not we manage to save an object with old data, be sure to remove it from the list, and continue with other objects.
Otherwise a bug like JENKINS-20950 can prevent *anything* from being saved, and holds references to all the old data.

Integrated the new version of XStream that contains the fix.

Protect the common thread pool against poorly written tasks that do not restore original context classloader.

Reference: RM-2329 in CloudBees

list-jobs should print names, not display names, since people expect to be able to feed the results into other CLI commands.

See comments in ce7e6390; and note reverted 71f3acfc.

This reverts commit 71f3acfc.
Test regressions

Not sure why it didn't in ce7e6390.

The fix allows to explicitly disable automatic page refreshes in the @view extensions.
Resolves https://issues.jenkins-ci.org/browse/JENKINS-21190Signed-off-by: NOleg Nenashev <o.v.nenashev@gmail.com>