Issue #2626570 by Wim Leers, thpoul, DuaelFr: Drupal 8's custom Image and Link plugins do not include a HiDPI icon

Issue #1494670 by Liam Morland, jhedstrom, Wim Leers, mfb: References to CSS, JS, and similar files should be root-relative URLs: avoids mixed content warnings & fewer bytes to send

Issue #2563543 by aneek, Wim Leers: CKEditor Toolbar - various button issues when the language is RTL