Issue #2557871 by alexpott: Remove all usages SafeMarkup::checkPlain() from template preprocess functions and attributes

Issue #2506195 by alexpott, joelpittet, xjm, David_Rothstein, Fabianx, pwolanin: Remove SafeMarkup::set() from Xss::filter()

Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

Issue #2398469 by DickJohnson, LewisNyman, emma.maria, kandra, mherchel: Clean up the "Featured-top" component in Bartik

Issue #1164784 by emma.maria, kattekrab, tadityar, DickJohnson, vermario, luco, Jeff Burnz, davidhernandez, David_Rothstein, webchick, Bojhan, LewisNyman, alexpott: “Triptych” term is not widely understood; add "Featured top" and "Featured bottom"

Issue #2392361 by emma.maria, ruscoe, vermario: Bartik theme: “triptych” and footer-columns classes added to body but never used in CSS

Issue #2217731 by crowdcg, lauriii, davidhernandez, aczietlow, jjcarrion, mortendk, karolus, pakmanlh, LewisNyman, aboros, joshua.boltz: Move field classes out of preprocess and into templates

Issue #2346369 by Wim Leers: Support special '#attached' variable for attaching assets in preprocess functions.

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 #1777332 by hass, Cottser, mike.roberts, joelpittet, dawehner | jenlampton: Replace theme_menu_link() and menu-tree.html.twig with a single Twig template.

Issue #1972122 by akalata, mortendk, JamesLefrère, pakmanlh, ckrina, sun: Remove the DIV tag around block content.

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.

Issue #2301599 by Cottser, mparker17: Fixed Regression: Bartik's field--taxonomy-term-reference.html.twig doesn't properly output label attributes.

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

Issue #1912610 by amitgoyal, BryanCGreen24, lokapujya, Rajendar Reddy, echoz, barraponto, LewisNyman, pixelwhip: Rename layout classes to follow the layout style naming convention.

Issue #2089331 by grom358 | thedavidmeister: [meta] Replace calls to check_plain() with Drupal\Component\Utility\String::checkPlain().

Issue #1533104 by visabhishek, bryanbraun, TravisCarden, majoely | NROTC_Webmaster: Make bartik theme pass Coder Review.

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

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

Broke update.php.

This reverts commit 10b03890.

Issue #1987398 by Nigel_S, Tim Bozeman, InternetDevels, adsw12, joelpittet, Cottser, mdrummond, dsayswhat, jerdavis, rteijeiro, LewisNyman, Rumato, gnuget: Field.module - Convert theme_ functions to Twig.

Issue #2203407 by nod_, sun: Replace #attached library array values with provider-namespaced strings.

Issue #1053648 by mdrummond, lokapujya, Cottser, Jeff Burnz, Les Lim, Gábor Hojtsy: Convert site elements (site name, slogan, site logo) into blocks.

Issue #1996238 by sun, nod_, damiankloip, Wim Leers, longwave, alexpott, Xano, mdrummond, Mark Carver, Jeff Burnz, highrockmedia, joelpittet, et al: Replace hook_library_info() by *.libraries.yml file.

Issue #2068471 by dawehner, Crell, tim.plunkett, jibran, fubhy, larowlan: Normalize Controller/View-listener behavior with a Page object.

Issue #1106344 by mgifford, BarisW: Taxonomy term reference field headers always should be rendered with a HTML header (invisible or not).

Issue #1982256 by mortendk, rteijeiro, tim.plunkett, LewisNyman, tlattimore, yannickoo, ry5n: Clean up html.html.twig markup.

Issue #2049207 by dlu, blakehall, janstoeckler, ramlev, Moderate | Cottser: Replace .tpl.php with .html.twig in documentation.

Issue #2040269 by Tim Bozeman, RunePhilosof, typhonius, Cottser: Remove drupal_add_css() from bartik.theme.

Issue #2011578 by mortendk, tlattimore, Cottser, soulston: Markup for Stark's page.html.twig + maintenance-page.html.twig.