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 #806982 by lokapujya, gnuget, miqmago, shashi1028, Floydm, bfroehle, kathyh, sreynen: Tables should take an optional footer variable and produce <tfoot>.

Issue #2227601 by mparker17, cs_shadow, swentel, lanchez, mgifford: Added a "Visually-hidden" field label formatter.

Issue #2296859 by Mark Carver: Fixed [regression] Responsive classes not always added to table rows.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Issue #2292025 by tim.plunkett: Convert BreadcrumbBuilderInterface applies() and build() to use RouteMatch.

Issue #2238217 by effulgentsia, neclimdul, martin107, tim.plunkett, cweagans, kim.pepper, xjm: Introduce a RouteMatch class.

Issue #1939092 by mgifford, dbazuin, jenlampton, azinoman, pwieck, Cottser, joelpittet, larowlan: Convert theme_mark() to Twig.

Issue #2052473 by ricky.middaugh, lokapujya, Jalandhar, mgifford, jessebeach, BarisW, falcon03: Add aria-label or aria-describedby attributes to all <nav> elements.

Issue #2152215 by joelpittet, mr.baileys, benjifisher, martin107, rteijeiro, hussainweb, shanethehat, jenlampton, kpa, AnythonyR, EVIIILJ, kgoel, Cottser, dsdeiz, hanpersand, bayousoft: Convert theme_form_element_label() to Twig

Issue #2152219 by joelpittet, mdrummond, rodrigoaguilera, sqndr, rteijeiro, InternetDevels, steveoliver, hussainweb, shanethehat, jenlampton, kpa, AnythonyR, EVIIILJ, kgoel, Cottser, dsdeiz, hanpersand: Convert theme_input() to Twig

Issue #2152205 by joelpittet, mark.labrecque, Manuel Garcia, pakmanlh, steveoliver, hussainweb, shanethehat, jenlampton, kpa, AnythonyR, EVIIILJ, kgoel, Cottser, dsdeiz, hanpersand: Convert theme_date() to #theme input__date

Issue #2246665 by jaredsmith, martin107, YesCT, filijonka, tstoeckler: Typehint with Drupal\Core\Language\LanguageInterface instead Drupal\Core\Language\Language.

Revert "Issue #806982 by lokapujya, gnuget, miqmago, shashi1028, Floydm, bfroehle, kathyh, sreynen: Tables should take an optional footer variable and produce <tfoot>."

This reverts commit 580fd45d.

Issue #806982 by lokapujya, gnuget, miqmago, shashi1028, Floydm, bfroehle, kathyh, sreynen: Tables should take an optional footer variable and produce <tfoot>.

Revert "Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel."

This reverts commit cda051c4.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Issue #788900 by ParisLiakos, dawehner, effulgentsia, xjm, et al: Deprecate and remove usages of arg().

Issue #2216437 by Wim Leers: Entity labels are not in-place editable on 'full entity page' (prime example: node title).

Issue #2152217 by joelpittet, mgifford, vijaycs85, jjcarrion, sun: Remove theme_form_required_marker() from the theme system - use CSS instead.

Issue #1939008 by sun, joelpittet, gnuget, Gokul N K, sphism, drupalninja99, c4rl, Cottser, mdrummond, long wave, steveoliver, andypost, Fabianx | jenlampton: Convert theme_table() to Twig.

Issue #1842326 by c4rl, sun, joelpittet, pakmanlh, jjcarrion | jenlampton: Merge _theme_table_cell() into theme_table().

Issue #1067408 by alexpott, Jalandhar, jessebeach, Désiré, neetu morwani, dawehner, sun: Themes do not have an installation status.

Issue #2152201 by Salah Messaoud, Manuel Garcia, steveoliver, joelpittet, burgerboydaddy, katy5289, hussainweb, shanethehat, jenlampton, kpa, AnythonyR, EVIIILJ, kgoel, Cottser, dsdeiz, hanpersand: Convert theme_checkboxes() to Twig

Issue #2218655 by sun, effulgentsia, jessebeach: Core expects $theme.settings default config file to exist.

Issue #2089433 by ianthomas_uk, grom358, herom, thedavidmeister, visabhishek, longwave, Sweetchuck: Remove uses of deprecated XSS filter functions.

Issue #2185617 by Wim Leers, voidberg, drifter: Each page cache entry should have a theme cache tag.

Revert "Issue #2218039 by sun, dawehner: Render the maintenance/install page like any other HTML page."

Broke update.php.

This reverts commit 10b03890.