Issue #3427741 by longwave, sakthi_dev, Spokje: Notify downstream users that ContainerAware is going away

Issue #3419909 by longwave, Spokje: Explicitly inject the container into ClassResolver and EntityTypeManager

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

Issue #2165475 by damiankloip, dawehner, martin107, tim.plunkett, jibran, xjm, Jalandhar: Provide a generic class resolver.