Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2447365 by JacobSanford, klausi, dawehner, jhodgdon, webchick: Let's explain in DestructableInterface why it is useful

Issue #1891980 by Berdir, amateescu: Add Service termination API to reliable terminate/shut down services in the container.