[JENKINS-34755] Migrate to SystemProperties and restrict access to the engine

* [JENKINS-34681] Allow custom default plugin managers

* [JENKINS-34681] Convert remaining properties to SystemProperties.

* [JENKINS-34733] - Allow overriding Jenkins UpdateCenter by a custom implementation

* [JENKINS-34733] - Reduce the logging level for the custom update center selection

* [JENKINS-34733 and JENKINS-34674] - Use SystemProperties in the UpdateCenter

* [JENKINS-28071] generalise BuildCommand target from AbstractProject to Job

This allows e.g. WorkflowJob to build, fixing symptom [JENKINS-29826]

* fixup! [JENKINS-28071] generalise BuildCommand target from AbstractProject to Job

* fixup! [JENKINS-28071] generalise BuildCommand target from AbstractProject to Job

* [JENKINS-34745] - Prevent CheckUpdates PeriodicWork death in the case of the missing update site signature

* [JENKINS-34745] - Fix typo in the validator

* [JENKINS-34745] - Fix the formatting of the validation message (cc @lanwen)

* Fix NPE getting size of parameterDefinitions.size

* Protect get against NPE

* readResolve and adequate List management

* [JENKINS-34370] Simplify code

* Address comments

* Address comments

* Use NullPointerException

[JENKINS-34755] - Allow setting of system properties from context.xml in addition to setting from command line

* [JENKINS-19445, JENKINS-34213, JENKINS-34808] Bump remoting to 2.58.

Changes:
* [JENKINS-34213](https://issues.jenkins-ci.org/browse/JENKINS-34213) - Ensure that the unexporter cleans up whatever it can each sweep (https://github.com/jenkinsci/remoting/pull/81)
* [JENKINS-19445](https://issues.jenkins-ci.org/browse/JENKINS-19445) Force class load on UserRequest in order to prevent deadlock on windows nodes when using JNA and Subversion (https://github.com/jenkinsci/remoting/pull/81)
* [JENKINS-34808](https://issues.jenkins-ci.org/browse/JENKINS-34808) - Allow user to adjust socket timeout (https://github.com/jenkinsci/remoting/pull/68)

* [JENKINS-34121] - Upgrade remoting to 2.59

Conflicts:
	core/src/main/java/hudson/FilePath.java

[JENKINS-31618] Fixed NoSuchMethodException in loginLink.jelly

BuildProcess: Update animal-sniffer-maven-plugin from 1.9 to 1.15.

[JENKINS-34767] - Prevent RSS ID collisions for items with same name in different folders

* [JENKINS-25164] Add SHORT_JOB_NAME env var

* Delete strip off

* [JENKINS-25164] Change SHORT_JOB_NAME for LEAF_JOB_NAME

* [JENKINS-25164] Change LEAF_JOB_NAME for JOB_BASE_NAME

Diff: https://github.com/jenkinsci/lib-annotation-indexer/compare/e90dade9a07b04b64ac1b08d539d30ad69ddf7a8...2eec43c72b3cd040d2057e6bbbf639f5e030453e

Major changes:
* 1.11 - [JENKINS-32978] support latest source version to avoid compile time warnings with JDK7
* 1.10 - Get ready for JDK 9
* 1.10 - Be tolerant against line separators on different operating systems
* 1.9 - Support of third-party annotations
* 1.8 - Annotation processor can be intercepted

The logic is moved from template back to Java and modified to fix the issue.
The argorithm is rewritten for better legibility.

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

Conflicts:
	core/src/main/java/hudson/Util.java
	core/src/main/java/hudson/WebAppMain.java
	core/src/main/java/hudson/model/Item.java
	core/src/main/java/hudson/model/Queue.java
	core/src/main/java/hudson/model/UpdateCenter.java
	core/src/main/java/hudson/security/csrf/DefaultCrumbIssuer.java
	core/src/main/java/hudson/slaves/NodeProvisioner.java
	core/src/main/java/jenkins/model/Jenkins.java
	core/src/main/java/jenkins/slaves/NioChannelSelector.java
	core/src/main/java/jenkins/util/xml/XMLUtils.java

Conflicts:
	changelog.html