FindBugs: get rid of the redundant null check in hudson.model.queue.Executables#getEstimatedDurationFor()

FindBugs: The tool cannot into StringUtils.isBlank(), so we optimize the code to workaround it (not a bug)

FindBugs: Handle the non-realistic case of null Staplerrequest in HudsonPrivateSecurityRealm#newInstance()

FindBugs: Violation of Descriptor newInstance() contract in hudson.scm.RepositoryBrowsers#createInstance deprecated method

FindBugs: Optimize logic of ChannelPinger#pingInterval initialization in order to fix the Integer unboxing issue in the original code

Queue.ItemList: Be sure we cleanup the list instead of the entire Queue (IA_AMBIGUOUS_INVOCATION_OF_INHERITED_OR_OUTER_METHOD)

* Move FindBugs call to the parent POM, always run it and generate XMLs

* Update FindBugs to 3.0.4

* Filter away Stream encoding issues

* Rework FindBugs definitions according to comments from @jtnord

* Generalize configuration, findbugs:findbugs now takes it.

* Add TODOs to FindBugs excludes file

* Remove explicit failOnError

* Fix the typo spotted by @jtnord

[JENKINS-21486] Fix plugin dependencies resolution, second round.

version

version

missing

messages between console and administrative monitor

* Check that dependencies are enabled. A disabled optional dependency
  will not prevent a plugin from loading.
* Check versions of dependencies declared by a plugin before loading it.
  If any dependency (even optional) is older than what is required,
  then the plugin isn't loaded.

This should prevent use cases where a plugin is loaded but one of its
dependencies is too old so that :
* its @Extension annotated classes cannot be loaded, causing the full
  Jenkins to blow up with crapload of exceptions which are tedious to
  investigate to understand the root cause.
* NoSuchMethodError and the likes at runtime even though boot has
  completed.

Version check (for setups where version list is manually crafted but yet
works) can be disabled by starting Jenkins with

-Dhudson.PluginWrapper.dependenciesVersionCheck.enabled=true

Minor fixes done while implementing this change :
* Fix version parsing in PluginWrapper.Dependency
* Dynamic plugin load didn't check for disabled flag

[JENKINS-37032] Add a UI to allow controlling enabled agent protocols

- Also switch the A/B testing of JNLP3-connect to via opt-in
- Also mark that JNLP3-connect will be deprecated by JENKINS-36871
- Also start A/B testing the disabling of JNLP-connect and CLI-connect (should be well safe by now)