Issue #3026043 by Berdir: ConfigEntityBase::__sleep() serializes plugin instances if they were not previously initialized

(cherry picked from commit 5fbbbde8)

Revert "Issue #2822382 by voleger, pfrenssen, erozqba, RytoEX, borisson_, sidharthap, Jo Fitzgerald, shashikant_chauhan: Make every  property protected on classes extending BrowserTestBase and KernelTestBase"

This reverts commit 29d0958a.

Issue #2822382 by voleger, pfrenssen, erozqba, RytoEX, borisson_, sidharthap, Jo Fitzgerald, shashikant_chauhan: Make every  property protected on classes extending BrowserTestBase and KernelTestBase

(cherry picked from commit 69501f30)

Issue #2937888 by dhruveshdtripathi, idebr, RoSk0, mohit1604, mfernea, borisson_: Fix 'Drupal.Commenting.DocComment.LongNotCapital' coding standard

Issue #2572613 by Malevi4, idebr, pfrenssen, Mile23, RajeevK: Fix 'Drupal.Array.Array.CommaLastItem' coding standard

Issue #2208429 by dawehner, almaudoh, alexpott, jibran, Xano, donquixote, amitgoyal, bircher, stefan.r, Mile23, alvar0hurtad0, Berdir, andypost, larowlan: Extension System, Part III: ExtensionList, ModuleExtensionList and ProfileExtensionList

Issue #2901572 by Jo Fitzgerald, bluccas, mfernea, klausi: Fix 'Drupal.Commenting.PostStatementComment' coding standard

Issue #2854529 by alexpott, xjm, klausi, Chi, Mixologic: Fix Drupal.Scope.MethodScope - all methods should have scopes

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2723589 by Ashish.Dalvi, gaurav.pahuja, marvin_B8, valthebald: Remove entity_load* usage for filter_format entity type

Revert "Issue #2723589 by Ashish.Dalvi, gaurav.pahuja, marvin_B8, valthebald: Remove entity_load* usage for filter_format entity type"

This reverts commit 39498e7d.

Issue #2723589 by Ashish.Dalvi, gaurav.pahuja, marvin_B8, valthebald: Remove entity_load* usage for filter_format entity type

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2679096 by Berdir, dawehner, tim.plunkett: Convert Kernel Tests in Drupal\system\Tests\Entity to phpunit

Issue #2503379 by Mac_Weber, DuaelFr, lluvigne, naveenvalecha, jmolivas: Replace deprecated usage of entity_create('filter_format') with a direct call to FilterFormat::create()

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 #2506581 by alexpott, Wim Leers, Fabianx, xjm, joelpittet, Cottser, dawehner: Remove SafeMarkup::set() from Renderer::doRender

Issue #2516802 by Dave Reid: FilterProcessResult->merge() results in PHP warning: Missing argument 1 for FilterProcessResult::__construct()

Issue #2392293 by bircher, tim.plunkett, alexpott, cilefen, gobinathm: Refactor hook_system_info_alter implementations to use ModuleUninstallValidatorInterface

Issue #2478483 by Wim Leers, Fabianx: Introduce placeholders (#lazy_builder) to replace #post_render_cache

Issue #2453059 by Wim Leers: Set default render cache contexts: 'theme' + 'languages:' . LanguageInterface::TYPE_INTERFACE

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

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

Issue #2432837 by Wim Leers, Fabianx: Make cache contexts hierarchical (e.g. 'user' is more specific than 'user.roles')

Issue #2090115 by alexpott, xjm: Don't install a module when its default configuration has unmet dependencies

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

Issue #2040135 by Wim Leers, Berdir: Caches dependent on simple config are only invalidated on form submissions

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

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

Issue #2340123 by Wim Leers: Setting cache tags can be tricky: use strings instead of nested arrays to improve DX.

Issue #2332885 by cs_shadow, Berdir, fago: Rename AllowedValuesInterface to OptionsProviderInterface.

Issue #2273277 by Wim Leers, effulgentsia, Fabianx: Fixed Figure out a solution for the problematic interaction between the render system and the theme system when using #pre_render.

Issue #2295129 by alexpott, tim.plunkett: Fixed Filter formats should not save plugin data when the plugin configuration matches defaults.