Moved Jenkins agent runtime to agent.jar file name, and deprecate (but still support) use of legacy slave.jar. Introduce the AGENTJAR_URL environment variable as replacement for SLAVEJAR_URL.
(issue 35451)
Internal: Implement DescriptorByNameOwner using Java 8 interface default method. Make Computer a DescriptorByNameOwner allowing its use as @AncestorInPath.
(pull 3009)