[JENKINS-32777] Cover 'delete-builds' CLI by tests

Conflicts:
	changelog.html

Slighty optimized and better legible asserts

[JENKINS-34710] - PluginWrapper should not throw IOException if somebody enables the enabled plugin (#2327)

* Remove CVS historical code - JENKINS-4610

* Fix whitespace issue

reload-configuration covered by test-cases

More details: https://issues.jboss.org/browse/WFLY-4782

see http://stackoverflow.com/questions/8185331/forward-compatible-java-6-annotation-processor-and-supportedsourceversion

[JENKINS-34674,JENKINS-34675] - Handling of the default update site ID

As detailed by @stephenc:

> So there is `getInstanceOrNull()` which is for use in Jenkins core or
> in code that plugins add that may escape the Jenkins singleton
> lifecycle.
>
> In regular plugins `getInstance()` will never return null as the
> lifecycle does not instantiate them until after there is a Jenkins
> singleton and the plugins will be stopped before there is no
> singleton.
>
> The `getActiveInstance()` is therefore equivalent to `getInstance()`
> and should never have been born.
>
> The only way a plugin can get a `null` from `Jenkins.getInstance()` is
> if you install an `atExit()` handler, use a `PhantomReference` type
> thing, or directly manipulate the servlet container in some way or
> other. A correctly written plugin should unwind any of those things
> when it is stopped or a method bound to the termination lifecycle. If
> there are some cases (for which I cannot anticipate a good coder being
> able to write a correct termination lifecycle method to fix) where the
> code cannot be unhooked... then in those cases the plugin should use
> `getInstanceOrNull()` and know how to respond to the `null` that could
> not be avoided.

[JENKINS-34328] CLI command disconnect-node extracted from core to CLI

[JENKINS-34683] - Do not print stack trace if plugin is missing dependencies

Workflow users may want to catch specific Exceptions without stracktrace in future.

* Add French translation on New Item screen

* Add French translation to Manage Jenkins page

* Add French translation to GlobalToolConfiguration page

* Add missing French translation to Manage Jenkins page

* Correct translations typos and PR remarks

HttpSession listener ExtensionPoint

[FIXED JENKINS-34675] - Prevent hanging of the WebUI if the default Update Site ID cannot be resolved.

Also hardens the Java code a bit.

[JENKINS-34601] Fix help file for node name attribute

[FIX JENKINS-31611] Restrict access to plugin pages

Lithuanian translation update

* [JENKINS-32936] Initial source code modifications

* [JENKINS-32936] Three views are using this approach

* [JENKINS-32936] Conflicts were resolved in a wrong way

disconnect-node extended to accept multiple node names
disconnect-node covered by test-cases