#1879120: Use Drupal-specific image and link plugins — use core dialogs rather than CKEditor dialogs, containing alterable Drupal forms added custom, Drupal-optimized "image" and "link" plugins for CKEditor.
Consequently we don't need to bundle CKEditor's default "image" and "link" plugins anymore, which cause the ckeditor.js file that is always loaded to be bigger for everybody.