Issue #2209029 by pwolanin: Follow-up: clean up use statements in book module code.
Issue #2203291 by alexpott: Invalid YAML in views.view.test_contextual_links.yml.
Issue #2029225 by cilefen, Cottser: Twig debug output does not show the base or derived hooks when a theme suggestion is called directly.
Issue #2204307 by EclipseGc: Move PluginBag Implementations from \Drupal\Component to \Drupal\Core.
Issue #2195675 by philipz, mdrummond, LewisNyman: Breadcrumbs push the sidebar down on node edit pages.