Bumping up core version for BuildStep-Job branch.
Can take advantage of new BuildListenerAdapter.
Sketch of CoreStep (naming TBD).
Merge branch 'master' into BuildStep-Job
Merge branch 'master' into BuildStep-Job
Fleshed out.
Merge branch 'master' into BuildStep-Job
Merge branch 'master' into BuildStep-Job

Conflicts:
	basic-steps/src/main/java/org/jenkinsci/plugins/workflow/steps/ArtifactArchiverStep.java
	pom.xml
Updated to #9.
Forgot to return a value! Easier to use AbstractSynchronousStepExecution.
Confirming that CoreStep does something.
Verifying that Fingerprinter works too.
Testing JUnitResultArchiver.
Merge branch 'master' into BuildStep-Job
Simplified XML.
Wrong syntax for failures.
Also verifying build status.
Merge branch 'master' into BuildStep-Job
Verifying that JavadocArchiver works.
Basic test of calling Mailer, for when the build result has already been set by JUnitResultArchiver.