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

- I was forgetting the call to `rebuildDependencyGraph()` which was why the test didn't work for me

- I suspect the synchronization on Jenkins is a bug also... but not causing the test failure, so will ignore for now

Otherwise you get:
java.lang.AssertionError: class org.jvnet.hudson.test.ExtractResourceWithChangesSCM is missing its descriptor
	at jenkins.model.Jenkins.getDescriptorOrDie(Jenkins.java:1166)
	at hudson.scm.SCM.getDescriptor(SCM.java:654)
	at hudson.scm.AutoBrowserHolder.get(AutoBrowserHolder.java:54)
	at hudson.scm.SCM.getEffectiveBrowser(SCM.java:136)
	at hudson.scm.ChangeLogSet.browserFromBuild(ChangeLogSet.java:82)
	at hudson.scm.ChangeLogSet.<init>(ChangeLogSet.java:76)
	at org.jvnet.hudson.test.ExtractChangeLogSet.<init>(ExtractChangeLogSet.java:41)
	at org.jvnet.hudson.test.ExtractChangeLogParser.parse(ExtractChangeLogParser.java:80)
	at org.jvnet.hudson.test.ExtractChangeLogParser.parse(ExtractChangeLogParser.java:52)
	at org.jvnet.hudson.test.ExtractChangeLogParser.parse(ExtractChangeLogParser.java:46)
	at hudson.model.AbstractBuild.calcChangeSet(AbstractBuild.java:894)
	at hudson.model.AbstractBuild.access$600(AbstractBuild.java:104)
	at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:634)
	at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:86)
	at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:528)
	at hudson.model.Run.execute(Run.java:1745)
	at …

This allows extensions to veto killing of certain processes.

Issue 9104 is not yet solved by this, it is only part of the solution. The
rest should be taken care of in plugins.

Squashed commits:
[73308b5] [FIXED JENKINS-27549] job loading can be broken by a NPE in a build trigger