Issue #2002138 by yched, Jose Reyero, xjm, andypost, fago, msonnabaum, Berdir, dixon_: Use adapters for supporting typed data.

Issue #2283977 by alexpott, Gábor Hojtsy, effulgentsia, fago: Create a new ConfigEntity type for storing bundle-specific customizations of base fields.

Issue #2223361 by Berdir, fago, tim.plunkett: Rename ComplexDataInterface::getPropertyValues() to toArray(), remove setPropertyValues().

Issue #2114707 by Berdir, yched, amateescu, effulgentsia, fago: Allow per-bundle overrides of field definitions.

Issue #2002134 by fago, yched, amateescu, effulgentsia: Move TypedData metadata introspection from data objects to definition objects.

Issue #2047229 by fago, smiletrl, Berdir, effulgentsia, amateescu: Make use of classes for entity field and data definitions.

Issue #2066535 by tim.plunkett, jsst, Berdir: Add EntityManagerInterface and stop typehinting with EntityManager.

Issue #2004244 by Berdir, plach, tim.plunkett, msonnabaum, das-peter: Move entity revision, content translation, validation and field methods to ContentEntityInterface.

Issue #1877632 by fago, jhodgdon: Improve comments and clean-up code for EntityNG and the TypedData API.

Issue #1761040 by sun, tim.plunkett, fago, effulgentsia: Rename Storable, Entity, and Configurable to Entity, ContentEntity, and ConfigEntity.