Issue #2549393 by alexpott, dawehner, lauriii, andypost, xjm: Remove SafeMarkup::escape() and rely more on Twig autoescaping

Issue #2426969 by David_Rothstein, joelpittet, dawehner: Dynamic redirects are no longer possible in the batch API (breaks updating existing modules or themes with the Update Manager)

Issue #2195183 by cleaver, sandykadam, elgordogrande, jhodgdon, joachim, Eda, hussainweb: document Batch API callbacks as callback implementations

Issue #2367743 by rpayanm, Miroling, YesCT, ianthomas_uk, shadik, gaurav.pahuja: Remove usages of drupal_form_submit() and update documentation

Issue #2335659 by tim.plunkett, dawehner, effulgentsia, sun: Remove FormState ArrayAccess usage from core.

Issue #1825952 by Fabianx, joelpittet, bdragon, heddn, chx, xjm, pwolanin, mikey_p, ti2m, bfr, dags, cilefen, scor, mgifford: Turn on twig autoescape by default

Issue #2121175 by Codenator, tim.plunkett, cosmicdreams, jayeshanandani, grom358, ianthomas_uk, Xano: Remove usage of drupal_get_form().

Issue #1979468 by Wim Leers, nod_, pwolanin, longwave, thedavidmeister, jessebeach, larowlan | catch: .active from linkGenerator(), l() and theme_links() forces an upper limit of per-page caching for all content containing links.

Revert "Issue #1979468 by Wim Leers, pwolanin, nod_, thedavidmeister, larowlan: .active from linkGenerator(), l() and theme_links() forces an upper limit of per-page caching for all content containing links."

This reverts commit 624296e7.

Issue #1979468 by Wim Leers, pwolanin, nod_, thedavidmeister, larowlan: .active from linkGenerator(), l() and theme_links() forces an upper limit of per-page caching for all content containing links.

Issue #2107531 by pwolanin, neclimdul, cilefen, dawehner, YesCT, tim.plunkett: Improve DX of local task YAML definitions.

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 #1987624 by disasm, robeano, piyuesh23, dawehner | vijaycs85: Convert batch_test() page callbacks to a new style controller.

Issue #2074509 by tim.plunkett, falcon03, mgifford, Xano: Fixed Add missing #title property to ensure form accessibility.

Issue #1668866 by ParisLiakos, aspilicious, tim.plunkett, pdrake, g.oechsler, dawehner, Berdir, corvus_ch, damiankloip, disasm, marcingy, neclimdul: Replace drupal_goto() with RedirectResponse.