Issue #1869476 by rteijeiro, LewisNyman, lauriii, Wim Leers, mdrummond, swentel, hosef, cbiggins, larowlan, sun, EclipseGc, Gábor Hojtsy: Convert global menus (primary links, secondary links) into blocks.

Issue #2301317 by pwolanin, dawehner, Wim Leers, effulgentsia, YesCT, xjm, alexpott: MenuLinkNG part4: Conversion.

Revert "Issue #2301317 by pwolanin, effulgentsia, Wim Leers, dawehner, alexpott: MenuLinkNG part4: Conversion."

This reverts commit fd2db9cd.

Issue #2301317 by pwolanin, effulgentsia, Wim Leers, dawehner, alexpott: MenuLinkNG part4: Conversion.

This reverts commit 07f63fe6.

Issue #2095121 by clemens.tolboom, jibran: Ensure every path in routing.yml files has a leading slash.

Issue #2070651 by pwolanin, dawehner, larowlan, tim.plunkett, ParisLiakos: Introduce a path-based breadcrumb builder, remove the one that's based on {menu_links()}.

Issue #1834002 by Gábor Hojtsy: Fixed Delete operations are all over the place. Remove tabs, provide title in routing.

Issue #2051097 by dawehner, Manuel Garcia, tlattimore, neclimdul: Change 'pattern' to 'path' in *.routing.yml files.

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

Issue #2012916 by andypost, Berdir, pwieck: Implement access controller for the menu and menu link entity.

This reverts commit 0f480b9e.

Issue #1946428 by foopang | mtift: Convert all of confirm_form() in menu.admin.inc to the new form interface.

Issue #1938008 by bxtaylor, floretan: Convert menu.module's system_config_form() to SystemConfigFormBase.