Issue #2005778 by webflo, naxoc, penyaskito, andypost, vijaycs85, plopesc, maggo: Convert language_admin_overview_form() to a Controller.

Issue #1833022 by e0ipso, plach, YesCT, kfritsche, penyaskito, vijaycs85, nod_, cam8001: Only display interface language detection options to customize more granularity.

Issue #1754246 by webflo, swentel, penyaskito, andypost, alexpott, YesCT, dagmar: Languages should be configuration entities.

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

Issue #111715 by andypost, swentel, tim.plunkett, sun, Berdir, amateescu, kkaefer, YesCT, dagmar, chx: Convert node/content types into configuration.

Issue #1888424 by katbailey, steveoliver, twistor, beejeebus, effulgentsia: Change notice: Make Drupal's URL generation logic available to HttpKernel, and minimize code repetition/divergence.

Issue #1974044 by EllaTheHarpy, IshaDakota, fjd, Schnitzel: Fixed 'Account administration pages' detection method confusing.

Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.

Issue #1898034 by Cottser, jenlampton, joelpittet, Shawn DeArmond, idflood, Hydra, artofeclipse, rich.yumul, chrisjlee, gnuget, c4rl, thund3rbox: block.module - Convert PHPTemplate templates to Twig.

Issue #1927608 by EclipseGc, tim.plunkett, effulgentsia: Remove the tight coupling between Block Plugins and Block Entities.

Issue #1827448 by RobLoach, sun, jbrown, tstoeckler: Use __DIR__ instead of DRUPAL_ROOT where possible/sensible.

Issue #1977784 by YesCT, Gábor Hojtsy, EllaTheHarpy: Content language settings configuration page needs to determine what entities and bundles to include.

Issue #1925738 by tim.plunkett: Followup: Convert language's system_config_form() to SystemConfigFormBase.

Issue #1446382 by plach: Need a reliable way to determine if a specific bundle for an entity type is translatable.

Issue #1502816 by joates: Add help text explaining the limitations of language negotiation and page caching.

Issue #1864066 by sun, andypost, tim.plunkett: Simplify hook_menu_local_tasks() and MENU_DEFAULT_LOCAL_TASK usage.

Issue #1899994 by katbailey, plach, YesCT: Disentangle language initialization from path resolution.

Issue #1871696 by tim.plunkett, xjm, sun, msonnabaum, EclipseGc: Convert block instances to configuration entities to resolve architectural issues.

Issue #1535868 by EclipseGc, tim.plunkett, xjm, Jody Lynn, sdboyer, naxoc, tizzo, effulgentsia, dawehner, disasm, beejeebus: Convert all blocks into plugins.

Issue #1810386 by plach, YesCT, Bojhan, bforchhammer, Gábor Hojtsy, falcon03: Create workflow to setup multilingual for entity types, bundles and fields.

Issue #1789750 by droplet: Fixed Fatal error: Call to undefined function language_negotiation_url_prefixes_update().

Issue #1739928 by vasi1186, YesCT, webflo, Transition, plach, Gábor Hojtsy: Generalize language configuration on content types to apply to terms and other entities.

Revert "Issue #1588422 by andypost, disasm, sun, dawehner, vasi1186, alexpott, tim.plunkett, larowlan, Gábor Hojtsy: Convert contact categories to configuration system."

This reverts commit 5cb63c4d.

Oops. That was a little more patch than we bargained for. :P

Issue #1588422 by andypost, disasm, sun, dawehner, vasi1186, alexpott, tim.plunkett, larowlan, Gábor Hojtsy: Convert contact categories to configuration system.

Issue #1480854 by tim.plunkett, Noyz, Bojhan, yoroy, kika: Convert operation links to '#type' => 'operations'.

Issue #365615 by attiks, smokris, penyaskito, Gábor Hojtsy, Bojhan, WormFood, yang_yi_cn: Fixed Language detection not working correctly for most Chinese readers.

Issue #1738330 by k4v, das-peter, jsbalsera, bforchhammer, Schnitzel: confusing Language negotiation when accessing /.

- Patch #322995 by Schnitzel, c31ck, webflo, penyaskito: provide a distinct administration user interface language option.

Issue #1739994 by pp, das-peter, Gábor Hojtsy: Use the Language class universally instead of stdObj instances.