[FIXES JENKINS-19622] Replace hudson.model.Trigger#timer with jenkins.util.Timer, which exposes a ScheduledExecutorService. Up to 10 additional threads will be created to run pending tasks even if running tasks are blocked.

Also, move static initialization of timers to the classes which require them.
We must still initialize and clean up the legacy Trigger#timer
Naming convention
Synchronize access to the ScheduledExecutorService so that we can avoid NPE's during failed startup and lazily initialize it safely.
Null check
Remove meaningless initialization
allow null from the name
[FIXED JENKINS-7285] Fix regression from 1.536
Now that we use Java 6, can finally deprecate IOException2.
Deprecating Hudson.getInstance.
Deleting code using @IgnoreJRERequirement for Java 5 compatibility.
Updated a couple of comments referring to Java 5.
Javadoc warning fixes for CLICommand, Run, and ViewOptionHandler
Merge pull request #1018 from MarkEWaite/javadoc-fixes-i

Javadoc warning fixes for CLICommand, Run, and ViewOptionHandler
A few usages of Hudson.getInstance() were actually mandated for use with method signatures which cannot compatibly be changed.
Random test failure.
Merge commit '8cd900362d3dc649ac838d8c062a610f4e4f0d66'
Merge branch 'scheduled-executor-timer' of github.com:recampbell/jenkins into recampbell-scheduled-executor-timer
[JENKINS-19622] Merged #989: allow background tasks to run simultaneously, preventing task blockage.
Avoid creating a mostly idle thread just to run a timed task.