[fixed JENKINS-18393] Do not list any ItemGroup in list-jobs CLI command

List item group recursively.
Add @Bug(18393) annotation
Merge branch 'master' into jenkins18393
Merge branch 'master' into jenkins18393
Add classes and ID's for common elements

This should aid theme developers in developing plugins for Jenkins by adding
CSS classes and ID's to the dom. Developers can then use these to more
specifically target elements that they want.

For example, the "Console Output" was a raw <pre> tag embedded in a <table>.
Styling it required CSS like so:

    #main-panel > pre {

Sadly this will apply to any <pre> elements nested directly under the
"#main-panel" ID; there's no way to get more specific to the console output.

With this change you can style the console output by writing:

    .console-output {

Which is much more direct (and more efficient for browsers to render).

A similar treatment is applied to a number of elements in the jenkins UI.
Add Java VM name

Java VM vendor cannot distinguish between various JVMs, e.g. OpenJDK returns Oraclde as a vendor.
Adding this property allows to distinguish between Oracle JVM and OpenJDK JVM.
Add more classes for disable project and description
[FIXED JENKINS-19947] Restore historical undocumented behavior of a top-level entry in a ZIP.
Noting that various DirScanner implementations handle this inconsistently.
[FIXED JENKINS-18629]

Consult Descriptor.newInstance() even when proccessing is in the middle
of JSON tree.
(cherry picked from commit d15c15506e8aaa757983a71c868ed58e0fd48827)
[FIXED JENKINS-14336]

Integrating the stapler fix.
Reuse compiled groovy script for more efficiency
this entire computation appears rather pointless since the result isn't getting used
Integrated the latest
[FIXED JENKINS-19926] Add only new env. variables

Previous patch (3eea39648943583a530f47f69f93737266537d9d) broke usescases when evn. variable overwrites already existing one
like PATH = $PATH:/my/path
updated German localization
purged orphaned messages
Merge branch 'master' of github.com:jenkinsci/jenkins
provide a means to synchronize on the completion of the maintenance, mainly for tests
Fixed a test failure.

Turns out in the new executor on-demand code, queue maintenance happens so quickly that even when a job is submitted with delay 0,
it can still fail the test if the check happens when "new GregorianCalendar()" returns the same value as "top.timestamp".

I'm relaxing that check
This module is no more