Conflicts:
	core/src/main/java/hudson/LocalPluginManager.java

Max Spring discovered a stack overflow in http://jenkins.361315.n4.nabble.com/channel-example-and-plugin-classes-gives-ClassNotFoundException-td3756092.html that pointed this call into thread context classloader (TCL) as the culprit. Independently, Paul Sandoz discovered the same issue in our products. If TCL is another classloader that delegates to UberClassLoader (UCL), this code causes infinite recursion.

And moreover, given the goal of UCL, it seems wrong that this class is changing behaviour based on contextual information like TCL.

 In looking at 4de81f1e, the change was introduced to make sure XStream unmarshalling invoked from Plugin.start() would see the classes in that plugin. This was an issue back then when plugins are prepared and loaded one by one, as UCL didn't have visibility into plugins being prepared. But in the current Jenkins, classloaders for all the plugins are prepared, before any plugin gets started, so by the time Plugin.start() runs, UCL is fully functioning.

 Therefore, there's no need to consult TCL for the purpose of resolving its own classes. I could have also removed the code that sets TCL, but because some libraries often depend on TCL and doesn't properly look at caller class, I'm leaving it in, even though it's generally a bad practice to rely on TCL in multi-classloader apps like Jenkins

not exposing the setBuiltOnStr to arbitrary external methods. It's really only for internal consumption.

Remove the shadow copy of buildOn from MavenBuild.java and move the setter to
AbstractBuild to allow MavenModuleSetBuild.java to continue to set the
build node.

following up tweaks to the previous commit, and explaining what we don't do so that future versions don't inadvertently mess up them

Add displayName and description as further optional tags that can be submitted as part of an External run

Use stock gmaven plugin to achieve this

fixed serving of JARs if running with hudson-dev:run which was broken since https://github.com/jenkinsci/jenkins/commit/a376eb5832a75d4fb840a9088b37a988582b0965

Ignore null reporters field in MavenBuild$RunnerImpl.post2 and avoid a NPE.
Thanks !

The NPE can occur if a build fails during checkout and hence the run phase
never gets called. See JENKINS-10831 for an example of this happening.

- Added a RenameListener to Fingerprint. When the listener is invoked for
  renamed projects, it will iterate over all the builds of the project looking
  for fingerprint actions. If the build was the originator of the fingerprint,
  the buildPtr is updated; (had to make the name non-final to allow for this).
  If the build is the consumer of a fingerprint, the usages are updated.

   core/src/main/java/hudson/model/Fingerprint.java

- Expose the fingerprint data inline with the build data in the remote API.
  The renaming code also uses this method as a convenient way to get the
  fingerprints for a build.

   core/src/main/java/hudson/model/AbstractBuild.java

- Test.

   test/src/test/java/hudson/tasks/FingerprinterTest.java

happen.

This happens because the version number isn't computed yet, but we try
to put that into HTTP header.

Fixing this by making <st:header/> tolerate null in value or name.