Issue #2459971 by Gábor Hojtsy: The langcode key on configuration files is not explicit in configuration schema

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

Issue #2291449 by Cottser: Add Twig template inheritance based on the theme registry, enable adding Twig loaders

Issue #2232477 by plach, yched, tstoeckler, amateescu: Fatal when adding new fields with NOT NULL constraints in a base table that contains existing entities

Issue #2068655 by Berdir, chx, martin107, longwave, webflo, damiankloip, lokapujya, JacobSanford: Entity fields do not support case sensitive queries

Issue #2347999 by Mile23, daffie, cs_shadow, cosmicdreams: DrupalUnitTestBase is deprecated, replace with KernelTestBase

Issue #2384487 by rpayanm, daffie, Sharique, areke: Make the class variables protected for FilterFormat

Issue #2380411 by areke, hussainweb, GPrince17: Clean-up Text module test members - ensure property definition and use of camelCase naming convention

Issue #2144505 by tstoeckler, YesCT, Gábor Hojtsy, vijaycs85, webflo: Views does not use the text format type for formatted text

Issue #2358529 by Tom Verhaeghe, Wim Leers, brylie, brahmjeet789, effulgentsia: Right-aligned images in CKEditor appear to the right of other fields

Issue #2370305 by Gábor Hojtsy, yched: Refactor field type configuration schemas for DX, easier to find errors

Issue #2378055 by Gábor Hojtsy: Reorganise config schema for entity_form_display / entity_view_display

Issue #2368349 by Gábor Hojtsy, alexpott: Entity view and form display configuration schemas are too verbose / key ones missing

Issue #2374815 by alvar0hurtad0: Update file comment on TextWithsummaryItemTest to show correct name

Issue #2340785 by mpdonadio: Create proper test method for determining if text has been escaped properly.

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

Issue #2312093 by alexpott, yched, andypost, swentel | xjm: Rename FieldInstanceConfig to FieldConfig.

Issue #2313757 by Berdir, Wim Leers, dawehner: Remove text_processing option from text fields, expose existing string field types as plain text in UI.

Issue #2320157 by moshe weitzman, Wim Leers, penyaskito, tim.plunkett: Generate placeholder content for Field types.

This reverts commit 3ac426f9.

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.