Issue #2030637 by yched, Mile23, daffie, Alumei, tidrif, chertzog, Berdir, swentel, ofry: Expand FieldConfig/BaseFieldOverride/FieldConfigBase with methods

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

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

Issue #2183983 by Gábor Hojtsy, vijaycs85, Berdir, Wim Leers, webflo, alexpott: Find hidden configuration schema issues

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

This reverts commit 3ac426f9.

Issue #1976158 by Berdir | msonnabaum: Rename entity storage/list/form/render "controllers" to handlers.

Issue #2287727 by yched, swentel, alexpott: Rename Field[instance]Config classes and entity types (again).

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

Issue #2257519 by sun, larowlan, xjm, cs_shadow: Move content assertion methods into a trait, so DUTB can consume it, too.

Issue #2143291 by plach, alexpott, xjm, effulgentsia, pwolanin, swentel | yched: Clarify handling of field translatability.

Issue #2089331 by grom358 | thedavidmeister: [meta] Replace calls to check_plain() with Drupal\Component\Utility\String::checkPlain().

Issue #2095195 by yched, fago, Berdir, amateescu, swentel, pfrenssen, Xano: Remove deprecated field_attach_form_*().

Issue #2095303 by swentel, plopesc, Berdir, claudiu.cristea, yched: Rename 'field_entity' to 'field_config' and 'field_instance' to 'field_instance_config'.

Issue #2097691 by plopesc, amateescu: Move FIELD_CARDINALITY_UNLIMITED constant to FieldDefinitionInterface.

Issue #2060705 by yched, Hydra, swentel, amateescu: Remove the 'hidden widget' plugin, it is actually never used.

Issue #1953408 by swentel, aspilicious, andypost, yched: Remove ArrayAccess BC layer from field config entities.

Issue #2074037 by Wim Leers, effulgentsia: Add drupalPostUrl() — drupalPost()/drupalPostAjax() are for forms only, D8 JS performs non-form HTTP requests.

Issue #2057869 by dawehner, jibran: Provide an alias for 'plugin.manager.entity' called 'entity.manager'.

Issue #1497374 by yched, chx, amateescu, plach, Damien Tournoud, fago, swentel: Switch from Field-based storage to Entity-based storage.

Issue #1822000 by Berdir, plach, amateescu, yched: Remove Drupal\field_test\Plugin\Entity\Type\TestEntity in favor of EntityTest.