[FIXED JENKINS-36494] Switch to a try with resources form of impersonation

* JENKINS-34668 - setup wizard installing panel unusable on small screens

[JENKINS-27530] nextBuildNumber snafu after reload

Remove the concept of yanking dead executors

[JENKINS-36494] Clarify that the previousContext is never `null` per JavaDoc for `SecurityContextHolder.getContext()`

So it cannot have been reverted.

[FIXED JENKINS-27530] Jenkins.reload must also reload the Queue to ensure that every Queue.Item.task corresponds to a live Job, lest nextBuildNumber be bogus.

[JENKINS-25416][JENKINS-28790] - Fix the parametersReferencedFromPropertiesShouldRetainBackslashes() test, which relies on the legacy behavior (#2435)

The test fails after https://github.com/jenkinsci/jenkins/pull/1976/commits/84ee34f2df620f1280022f1678b81e5c27dfc330

[FIXED JENKINS-25416][JENKINS-28790] Do not inject build variables into maven process optionally (#1976)

* [FIXED JENKINS-25416][JENKINS-28790] Do not inject build variables into maven process optionally

* [JENKINS-25416][JENKINS-28790] Fixed typo in test method name

* [JENKINS-25416][JENKINS-28790] Suggest alternatives in help

* [JENKINS-25416][JENKINS-28790] Use less hackish approach to preserving legacy behaviour

* [JENKINS-20187] - Handle growing files when creating a tar file.

* - Introduce try-with-resources
- Remove exception login
- Throw new exception with filename and addSuppresed

* Address jglick comments

[FIXED JENKINS-36280] Enable DescriptorVisibilityFilter for Slave's C…

* [FIXED JENKINS-35906] Ensure that SCMDescriptor.newInstance overrides are honored.

* [FIXED JENKINS-36043] Work around fragile form submission design in multi-branch-project-plugin.

* [FIXED JENKINS-36232] NPE during SCM polling

* add test to trigger the "no veto" code path that has the NPE

* incorporate remark on using @Issue reference

Make BulkChange auto-closeable

Without it version of optional dependencies is set to "X.Y;resolution:=optional" which causes problems when using hudson.util.VersionNumber comparison methods.

Tests did not match naming pattern so were never being executed

The tests pass locally, but they will not run until #2429 is merged

Divergence introduced with 117d69b8.