Issue #2066535 by tim.plunkett, jsst, Berdir: Add EntityManagerInterface and stop typehinting with EntityManager.

Issue #2099095 by jibran, tim.plunkett: Create BreadcrumbBuilderBase and remove the boilerplate code from BreadcrumbBuilders.

Issue #731724 by larowlan, andypost, dixon_, tsvenson: Convert comment settings into a field to make them work with CMI and non-node entities.

Issue #1981368 by tim.plunkett, Crell, webchick: Convert all routes to 'module_name().foo_bar()' naming convention.

Issue #1978958 by jibran, disasm, kgoel, Pancho, vijaycs85, cosmicdreams, dawehner, wamilton: Convert comment_reply() to a Controller.