Issue #2194807 by longwave, tim.plunkett: Remove obsolete CSS for language admin form.
Issue #2208395 by cosmicdreams, dawehner: Fix types in docs in BookManagerInterface
Issue #2208649 by joachim, Crell: Improve documentation of queue hook by defining a callback function template
Issue #2207557 by longwave: Fix docs for SortArrayTest
Issue #2209583 by ianthomas_uk: Remove use of drupal_set_title()/drupal_get_title()/_system_path from page cache.
Issue #2202671 by Mark Carver, tim.plunkett: Rename CSS_SKIN constant to CSS_THEME.
Issue #2192653 by ianthomas_uk, divesh.kumar: Remove drupal_set_title from authorize.php.
Issue #2188897 by cam8001: Intermittent fails in Drupal\views_ui\Tests\DisplayTest.
Issue #1987694 by ianthomas_uk, disasm, rlmumford, vijaycs85: Convert entity_test callbacks to a new style controller.
Issue #2170425 by miraj9093, sandipmkhairnar, tgeller: Make text consistent: "Add new content" -> "Add content".
Issue #2203435 by sun: Move all external libraries from core modules into core.libraries.yml.
Issue #2187717 by sun, dawehner: Remove code duplication in system_list() and ThemeHandler::rebuildThemeData().
Issue #2191011 by Stuart Miller, Cottser: PHP Warnings in views_preprocess_page() caused by frontpage view.
Issue #2209071 by tstoeckler: StringItem should cast the 'length' schema value to (int).
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.
Issue #2202143 by alexpott, benjy: Multiple calls to ConfigFactory::get() inside t() is unnecessary.