[JENKINS-60381] Remove old, deprecated agent protocols.#4387

Merged

oleg-nenashev merged 5 commits intojenkinsci:masterfrom jeffret-b:removeDeprecatedProtocols

Jan 10, 2020

+201-953

Commits on Dec 4, 2019

Remove deprecated agent protocols.
jeffret-b
committed

Commits on Dec 20, 2019

Cleanup JavaDoc from references to removed classes.
jeffret-b
committed

Commits on Jan 3, 2020

Commits on Jan 6, 2020

Add back in AgentProtocolTest.
jeffret-b
committed