Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2481453 by dawehner, pwolanin, rteijeiro, neclimdul, znerol: Implement query parameter based content negotiation as alternative to extensions

Issue #2286971 by znerol, Berdir, almaudoh, cilefen: Remove dependency of current_user on request and authentication manager

Issue #2350837 by dawehner, Berdir, larowlan, Wim Leers: Convert most usages of EntityInterface::getSystemPath() to use routes

Issue #2318753 by greenhodge, amitgoyal, Devin Carlson: REST Module: Fix documentation that refers to enabling/disabling of modules

Issue #2343661 by larowlan, tim.plunkett | xjm: Rename l() to _l() and url() to _url(), and document replacements.

Issue #2063303 by dawehner, damiankloip, Wim Leers: Fixed A Drupal 8 AjaxResponse that must return a 403, returns a 403 and prints 'A fatal error occurred: '

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2182055 by dawehner, andypost, juampy, linclark: Comment module causes Circular reference error on a REST request.

Issue #2099679 by linclark: Fixed Changing the order of asserts in AuthTest::testRead makes them fail.

Issue #2041885 by BTMash, cweagans, klausi: Move HTTP basic authentication provider to a separate module.

Issue #1987814 by juampy, tim.plunkett, lliss, kushrohra: Convert system_admin_menu_block_page() to a new style controller.

This reverts commit a567be3e.