Issue #2533776 by nicolas.rafaelli, lluvigne, dagmar: Instead of mocking TypedDataManager, use TypedDataManagerInterface in tests

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

Issue #2227227 by mpdonadio, amateescu, yched, larowlan, swentel, tstoeckler, fago: FieldTypePluginManager cannot instantiate FieldType plugins, good thing TypedDataManager can instantiate just about anything

Issue #2273311 by donquixote, xjm: Fixed FieldDefinitionTestBase::getNamespacePath() breaks with PSR-4.

Issue #2257769 by tstoeckler | sun: Adding an Entity Reference field in the Field UI throws a PHP notice; fails to add field.