CommandLauncherTest is flaky

[FIXED JENKINS-23150] Plugin Manager - Only allow enable/disable/uninstall when all dependants or dependencies are disabled/enabled

[JENKINS-28781] update the bct library to 1.6.2.

Pickup the changes in the bytecode-compatibility-transformer for
JENKINS-28781

* master:
  Update the changelog by new merges:
  [FIXED JENKINS-30569] HistoryWidget: fix JS syntax error
  [FIXED JENKINS-29014] render API link conditional on getApi() presence
  [JENKINS-21720] JS alert preventig to leave a configuration page even without formulary changes
  add ctags file 'tags' to .gitignore
  [maven-release-plugin] prepare release jenkins-1.632
  [FIXED JENKINS-29888] Handling all exceptions returned by logRotator
  [JENKINS-30742] Fixed possible NPE in AbstractProject.resolveForCLI()

* JENKINS-29888 - https://github.com/jenkinsci/jenkins/pull/1790
* JENKINS-30742 - https://github.com/jenkinsci/jenkins/pull/1849
* JENKINS-29014 - https://github.com/jenkinsci/jenkins/pull/1850
* JENKINS-21720 - https://github.com/jenkinsci/jenkins/pull/1854
* JENKINS-30569 - https://github.com/jenkinsci/jenkins/pull/1856

[FIXED JENKINS-29888] - Handling all LogRotator exceptions

[JENKINS-30742] Fixed possible NPE in AbstractProject.resolveForCLI()

[maven-release-plugin] copy for tag jenkins-1.632

[FIXED JENKINS-29014] fix broken 'REST API' link

add ctags file 'tags' to .gitignore

[JENKINS-21720] JS alert preventing to leave a configuration page without changes

[FIXED JENKINS-30569] HistoryWidget: fix JS syntax error

* master: (58 commits)
  Changelog: Replace the PR reference by the JIRA issue reference
  Noting https://github.com/jenkinsci/jenkins/pull/1818
  Noting https://github.com/jenkinsci/jenkins/pull/1804
  [JENKINS-30002] Improve Util.isOverridden
  Noting #1842
  [FIXED JENKINS-30777] this concludes the fix
  [JENKINS-30777] also allow slaves to decorate logger
  [JENKINS-30777] Generalized the signature to work with Run, not just AbstractBuild.
  Diamond operator
  [FIXED JENKINS-29876] CheckForNull job in ReverseBuildTrigger
  Noting JENKINS-30084 in changelog
  [JENKINS-30084] remove extra space
  [JENKINS-30084] address feedbacks
  [JENKINS-30084] indent back
  [JENKINS-30084] fixing test
  [JENKINS-30084] fixing test
  [JENKINS-30084] enhancing test case
  [JENKINS-30084] test added to make sure a flyweight task can be blocked at last minute
  [JENKINS-30084] fix regression when flyweight task is blocked by upstream/downstream project
  [JENKINS-30084] some more polish
  ...

For example https://ci.jenkins-ci.org/job/jenkins_main_trunk/4281/testReport/hudson.slaves/CommandLauncherTest/commandSuceedsWithoutChannel/
java.lang.AssertionError: 
Expected: a string containing "ERROR: Process terminated with exit code 0"
     but: was "… Launching slave agent
$ true
ERROR: Unable to launch the slave agent for dummy
…java.io.EOFException: unexpected stream termination
	at hudson.remoting.ChannelBuilder.negotiate(ChannelBuilder.java:333)
	at hudson.remoting.ChannelBuilder.build(ChannelBuilder.java:282)
	at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:365)
	at hudson.slaves.CommandLauncher.launch(CommandLauncher.java:130)
	at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:238)
	at jenkins.util.ContextResettingExecutorService$2.call(ContextResettingExecutorService.java:46)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:722)
"
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:8)
	at hudson.slaves.CommandLauncherTest.commandSuceedsWithoutChannel(CommandLauncherTest.java:67)

Add task-icon-link class to left menu

[JENKINS-30002] Improve Util.isOverridden

[FIXED JENKINS-29876] CheckForNull job in ReverseBuildTrigger