Issue #2940038 by Sweetchuck, drunken monkey, rajeshwari10, borisson_: Use $this in @return PhpDoc comments instead of the name of the current class or interface

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

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

Issue #2531570 by mondrake, MattA, claudiu.cristea: Image objects should release memory when losing scope

Issue #2096703 by mondrake, tim.plunkett | tstoeckler: Image toolkits should use PluginFormInterface and ContainerFactoryPluginInterface.

Issue #2211227 by mondrake, xjm | fietserwin: Refactor image and imagetoolkit: isExisting, isSupported, supportedTypes, getMimeType.

Issue #2217783 by mondrake: Remove $extension and $mimeType from Image, use image_type_to_xxx function in the getters instead.

Issue #2103621 by mondrake | fietserwin: Move GD logic from ImageInterface to toolkit, tie toolkit instance to Image instance, toolkits should no longer be instantiated separately.

Issue #2048827 by claudiu.cristea, tim.plunkett: Move Image toolkit API from system.module to Drupal\Core.

Issue #1664844 by alexpott, cweagans, heyrocker, eojthebrave, ACF, Berdir: Convert image toolkits into plugins.