Implemented the hook

in preparation of introducing other hooks

[FIXED JENKINS-7285] Fix regression from 1.536

Integrated the fix in Stapler.

Added NamingThreadFactory to ensure that all code creating thread pool executors was marking the threads.
Otherwise we get a bunch of pool-17-thread-5 with no clue who created so many threads or why.
Also simplifies existing code which previously had to write one-off ThreadFactory implementations just to set a name.

[JENKINS-19622] Merged #989: allow background tasks to run simultaneously, preventing task blockage.

Merge branch 'scheduled-executor-timer' of github.com:recampbell/jenkins into recampbell-scheduled-executor-timer

A few usages of Hudson.getInstance() were actually mandated for use with method signatures which cannot compatibly be changed.

Javadoc warning fixes for CLICommand, Run, and ViewOptionHandler

If TopLevelItemDescriptor.newInstance throws a RuntimeException, why are we wrapping it in an IllegalArgumentException?
Let it throw something like Failure and control the rendering.

Remove weird chars from Javadoc.

Probably a copy+paste caused these extra characters in there.