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

Issue #1851414 by nod_, quicksketch, frega, dawehner, damiankloip: Convert Views to use the abstracted dialog modal.

Issue #1839318 by JohnAlbin, echoz: Added Replace drupal.base.css library with normalize.css for all themes.

Issue #1965650 by Pancho, mradcliffe, manningpete, rabbit_media, DeeLay: Fixed Comment rendering broken: comment body rendered outside of the bubble.

Issue #1879120 by quicksketch, Wim Leers, larowlan, frega: Use Drupal-specific image and link plugins — use core dialogs rather than CKEditor dialogs, containing alterable Drupal forms.

Issue #2015789 by fubhy, echoz, rteijeiro, LewisNyman, penyaskito: Remove language_css_alter() (RTL stylesheets) in favor of HTML 'dir' attribute.

Issue #1363112 by mparker17, mgifford, tlattimore, Jacine, dcmouyard, bowersox, ry5n, ahdiaz: Simplify names of 'element-x' helper classes.

Issue #1973456 by echoz: Fixed .element-invisible on element at right causes horizontal scrollbar on desktop or right gap on phone on webkit browsers.

Issue #1847084 by jessebeach, trawekp, LewisNyman, nod_, tarekdj: Fixed Vertical toolbar doesn't work with overlay (measure/track displacing elements better + provide change events for them).

Issue #1913958 by hass, YesCT: Fixed Bartik theme: Don't change capitalization of translatable strings with CSS.

Issue #1168246 by sun, mgifford, Manuel Garcia, mbrett5062, ry5n, Everett Zufelt, nod_, aspilicious, deviantintegral, tim.plunkett: Freedom For Fieldsets! Long Live The DETAILS.

Issue #1292470 by sun, tim.plunkett, Berdir, moshe weitzman, pcambra, Niklas Fiekas, andypost et al: Convert user pictures to Image Field.

Issue #1238484 by mrfelton, ry5n, aspilicious, Bojhan, Xano, nod_, rootatwc, effulgentsia, chx, sun: Ability to mark the form buttons to be of a specific type (so that they can be styled differently).

Issue #1826574 by dawehner, dead_arm, tim.plunkett: Move Views theme-specific CSS to their respective themes.

Issue #1608878 by jessebeach, tim.plunkett, dead_arm, nod_, sun, effulgentsia, Everett Zufelt, geerlingguy: Added CTools dropbutton to core.

Issue #1276908 by jessebeach, nod_, moshe weitzman, lewisnyman, webchick: Fixed Administrative tables are too wide for smaller screens.

- Patch #1192044 by mjohnq3, Manuel Garcia, effulgentsia, sun, JohnAlbin, jessebeach, moshe weitzman: Convert Bartik's layout to mobile-first and responsive.