Issue #2192259 by andypost, amateescu, damiankloip: Remove ConfigField.. Item and List classes + interfaces.
Issue #2002134 by fago, yched, amateescu, effulgentsia: Move TypedData metadata introspection from data objects to definition objects.
Issue #2152825 by plopesc, swentel, Berdir: Rename FieldItemBase::getFieldSetting[s]() to getSetting[s]().
Issue #2156337 by yched, amateescu, smiletrl: Merge ConfigEntityReferenceItemBase up into EntityReferenceItem, and fix inconsistencies.
Issue #2015687 by smiletrl, amateescu, Berdir, fago: Convert field type to FieldType plugin for taxonomy module.