Drupal Core API changes
- Add DateTimePlus::getDateTimeObject() for situations that require a DateTimeInterface
- Expose oEmbed provider URL setting in the Media configuration form

Drupal Core Improvements
- preAutoloadDump
- Telephone Link field formatter InvalidArgumentException with 5 digits or fewer in the number
- Unique field constraint does not work with entity reference fields
- Taxonomy "Reset to alphabetical" doesn't clear cache of entities
- Modal popups in views is not showing properly when toolbar tray is upon modal
- Add missing "\" before full class name
- Fix grammar ("an URL" should be "a URL") and consistent use of URL (not "url" / "Url")
- Add @internal to core classes, methods, properties to Controllers
- UniqueFieldConstraint doesn't work for entities with string IDs

Drupal Core UI Improvements
- UniqueFieldValueValidator lowercasing Label of field on violation message
- Modal popups in views is not showing properly when toolbar tray is upon modal

Drupal Core Automated tests
- Fix BlockContentAccessHandlerTest::providerTestAccess wrong coverage by early return
- Extend the CKEditorIntegrationTest for DrupalImage
- Extend the CKEditorIntegrationTest for DrupalImageCaption
- Convert web tests to browser tests for image module
- Update "Running tests" section in core.api.php

Contributed modules improvements
Patches for Search API Attachments
- FilesExtrator
Patches for D8 Editor Advanced link
- PHP 7.1 compliance