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

Issue #2196907 by divesh.kumar: Convert all calls & docs references to check_plain() in core to Drupal\Component\Utility\String::checkPlain() in link module.

Issue #1898426 by Floydm, Cottser, jenlampton, chrisjlee, kattekrab, jerdavis, derheap, hussainweb: link.module - Convert theme_ functions to Twig.

Issue #1969728 by yched, effulgentsia, swentel, fago, plach: Implement Field API 'field types' as TypedData Plugins.

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.

Issue #1839080 by Berdir, fago, dasjo, jjchinquist: Implement the new entity field API for the link field type.

Issue #1874300 by Berdir, swentel: Remove $entity_type argument from field.module functions that receive a single $entity.

Issue #1241938 by swentel, Niklas Fiekas, yched: Added support for #placeholder to relevant Field API widgets.