[FIXED JENKINS-26751] Do not run /script on offline slave

[FIXED JENKINS-21322] Configure periodic ws cleanup

[JENKINS-20989] PeepholePermalink RunListenerImpl oncompleted should be triggered before downstream builds are triggered

This reverts commit fe1a1487.
It's been about a month, so I think it has served its purpose.

[JENKINS-26698] Localization follow-up

[JENKINS-27392] SimpleBuildWrapper.createLoggerDecorator

Allowing some methods to be overridden, with the caveat that the overrides will not be called from CoreWrapperStep.

Update README.md; Grammar/Spelling, recommended license format

Fix load statistics description

Allow control over the creation of different TopLevelItems from the ACL

Set proper socket parameters suitable for CLI communication

Keep-alive option ensures that the connection won't hang forever. NoDelay option improves performance as the communication over the socket is already datagram oriented.

See: https://developer.cloudbees.com/bin/view/DEV/On-Premise+Executors