Issue #2084987 by andypost, Jalandhar: Remove usage of field_ui_default_value and recommend proper replacement

Issue #2347465 by tim.plunkett, dawehner, cilefen: Convert all instances of #type link/links to convert to use routes.

Issue #2335659 by tim.plunkett, dawehner, effulgentsia, sun: Remove FormState ArrayAccess usage from core.

Issue #2308821 by tim.plunkett: Replace FormErrorInterface with $form_state->setErrorByName() and $form_state->setError().

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

Issue #2054011 by amateescu, pwolanin, dawehner, YesCT, tim.plunkett, blueminds, Berdir, das-peter, effulgentsia: Implement built-in support for internal URLs.

Issue #2136197 by andypost, jessebeach, swentel, longwave, Berdir: Move field/instance/widget/formatter settings out of annotation / plugin definition.

Issue #2050835 by Berdir | yched: Move Widget, Formatter, and FieldType plugin types to the Core\Field system.

Issue #2051923 by Berdir, dixon_, plach: Rename \Drupal\Core\Entity\Field\Field, related subclasses and interfaces to *FieldItemList.

Issue #2021817 by effulgentsia, yched: Make widgets / formatters work on EntityNG Field value objects.

Issue #1950632 by effulgentsia, Wim Leers, amateescu, yched: Create a FieldDefinitionInterface, decoupled from  and  config entities, and use it for formatters and widgets.

Issue #1801268 by falcon03, mgifford, Risse, heddn, larowlan: Change link field 'title' field to 'link text'.

Issue #1796316 by netsensei, swentel, jibran, zuuperman, amateescu: Convert Link/URL widgets / formatters to plugin system.