Issue #2260061 by Jelle_S, attiks, Wim Leers, mdrummond, mgifford, holist: Responsive image module does not support sizes/picture polyfill 2.2

Issue #2142653 by corbacho, sqndr, LewisNyman, floretan, BarisW, G-raph, JamesLefrère, lokapujya, LoMo, Outi: Change default logo filetype to .svg and add an SVG version of Druplicon

git commit -m 'Issue #2377397 by Wim Leers, alexpott: Themes should use libraries, not individual stylesheets'

Issue #2271529 by attiks, alexpott, Lowell, YesCT, Jelle_S | mdrummond: Move breakpoint settings to theme and module *.breakpoints.yml files at root level.

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

Issue #2233787 by alexpott, xjm | tim.plunkett: Move default configuration into extension/config/install to clarify its purpose.

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

Issue #922696 by mgifford, EvanDonovan, LewisNyman, stpaultim, jensimmons: New methods, standards for describing core themes on themes admin page (was Theme screenshots do not have adequate alt text...).

Issue #2167623 by danilenko_dn, sidharthap, Nitesh Sethia, krishnan.n, aitiba, alexpott, ashwinikumar, Barrett, damiankloip, deepakaryan1988, foxtrotcharlie, ianthomas_uk, neetu morwani, nonsie, piyuesh23, Sharique, sivaji, sushantpaste, swentel, vijaycs85, YesCT: Add test for all default configuration to ensure schema exists and is correct.

Issue #2117441 by alanburke: Fixed Stark layout broken as 'generic' classes removed from html.tpl.php.

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

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

Issue #1712250 by alexpott, n3or, cam8001, vijaycs85, Albert Volkman, jibran, heyrocker, chx: Convert theme settings to configuration system.

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

- Patch #1645494 by effulgentsia: Allow core themes to display single-column on IE8: do not compensate for lack of media query support.

- Patch #1322794 by scor: follow up patch fixing the 'No newline at end of file' in ie-rtl.css and ie.css.

- Patch #1322794 by JohnAlbin, alanburke, jrbeeman, rupl, Tor Arne Thune: make Stark use a responsive layout.

Nate Lampton authored Oct 30, 2011 and catch committed Nov 01, 2011

Issue #22336 by quicksketch, scor, boombatower, and rfay. Move all core Drupal files under a core subdirectory.

Revert "Issue #22336 by quicksketch, rfay, scor, Rob Loach, boombatower, tstoeckler, kbahey: Move all core Drupal files under a /core folder to improve usability and upgrades."

This reverts commit f0a16bf2.

Issue #22336 by quicksketch, rfay, scor, Rob Loach, boombatower, tstoeckler, kbahey: Move all core Drupal files under a /core folder to improve usability and upgrades.