Issue #2641528 by heykarthikwithu, Mac_Weber, naveenvalecha: Replace deprecated usage of  entity_create('editor') with a direct call to Editor::create()

Issue #2307141 by mbaynton, mgifford, Wim Leers: Enable browsers' (native) spell checker in CKEditor

Issue #1494670 by Liam Morland, jhedstrom, Wim Leers, mfb: References to CSS, JS, and similar files should be root-relative URLs: avoids mixed content warnings & fewer bytes to send

Issue #2541252 by HOG, finnsky, LewisNyman, nlisgo, saki007ster, alvar0hurtad0, maris.abols, pjbaert, bruvers, emma.maria, ti2m: Replace the .region-content ul/ol selector with text-formatted

Issue #2596083 by Wim Leers, lokapujya, jamin_melville: Allowed attribute 'class' not respected in CKEditor: ACF strips it

Issue #2549077 by pwolanin, Wim Leers, phenaproxima, lauriii: Allow the "Limit allowed HTML tags" filter to also restrict HTML attributes, and only allow a small whitelist of attributes by default

Issue #2566447 by stefan.r, joelpittet, alexpott, lauriii, dawehner: Cast safe string objects to string or use assertEqual() in some assertIdentical() comparisons

Issue #2552175 by nlisgo, Wim Leers: Follow-up for #2398463: Bartik is telling CKEditor to load a CSS file that no longer exists

Issue #2552187 by Wim Leers, LewisNyman: Follow-up for #2395853: CKEditor is loading system.modules.css, which no longer exists

Issue #2521906 by mErilainen, LewisNyman, Bojhan, eliza411, ivanstegic, lunk_rat, nickrosencrans, stpaultim, Mark LaCroix, webchick: Add default configuration to support h2-h6 level headings

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2451665 by dawehner: Don't rebuild the route on ModuleInstaller::install() (30% installer speedup)

Revert "Revert "Issue #2457653 by Gábor Hojtsy: System.site langcode is both used as a file language code and a site language code""

This reverts commit 079a52b4.

Revert "Issue #2457653 by Gábor Hojtsy: System.site langcode is both used as a file language code and a site language code"

This reverts commit 364a6e9c.

Issue #2457653 by Gábor Hojtsy: System.site langcode is both used as a file language code and a site language code

Issue #356399 by dawehner, beejeebus, catch, sidharrell, klausi, nlisgo, Josh Waihi, Berdir, martin107: Optimize the route rebuilding process to rebuild on write

Issue #2415855 by emma.maria: A forgotten reference to list.css in Bartik's info file is giving core a 404 error

Issue #2064379 by tadityar, bneil: Remove ckeditor-iframe.css and load relevant Bartik CSS files for CKEditor's iframe mode

Issue #2392319 by alexpott, effulgentsia: Config objects (but not config entities) should by default be immutable

Issue #2318237 by Gábor Hojtsy, bserem, no_angel, Wim Leers: CKEditor translates its user interface even if interface translation is turned off

Issue #2395395 by alexpott, effulgentsia, Gábor Hojtsy: TestBase lacks a config method to be used consistently in tests

Issue #2385111 by tadityar, Wim Leers: Bartik's CKEditor iframe stylesheet is not being loaded, hence image captions look broken

Issue #2361681 by Wim Leers: drupal_render(): invert second argument ($is_recursive_call -> $is_root_call) => more strict, better DX/TX.

Issue #2342633 by Wim Leers, wwalc: Fixed CKEditor context menu broken due to an error in the drupalimage plugin.

Issue #2350289 by mitrpaka: Replace extend of deprecated DrupalUnitTestBase with KernelTestBase in CKEditor.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2030605 by tim.plunkett, mr.baileys, webwarrior, Wim Leers | plopesc: Expand Editor with methods.

Issue #2219499 by Berdir, alexpott, Gábor Hojtsy, vijaycs85, swentel: Generalize language config override responsibility.

Issue #2080823 by alexpott, swentel, Wim Leers: Create API to discover content or config entities' soft dependencies and use this to present a confirm form on module uninstall.

Issue #2204129 by Wim Leers, tim.plunkett: Store the filter format on the editor entity during runtime.

Issue #2170085 by Wim Leers, jessebeach: Caption filter may not wrap images that are only aligned, not captioned.