Issue #2428377 by sun, daffie, amateescu: SQLite Schema class is missing use Drupal\Component\Utility\Unicode

This reverts commit d1a9a099.

Issue #2425691 by pjbaert, kepford, drupalninja99: Remove .leaf/.menu-item--leaf from menu CSS components

Issue #2426031 by almaudoh, cpj: Remove deprecated uses of SessionManager::isEnabled(), SessionManager::enable() and SessionManager::disable()

Issue #1946090 by pjonckiere, alex-mo, rpayanm: _drupal_wrap_mail_line() does not force-wrap too long words after 996 characters

Issue #2423241 by Mile23: Merge ConfigurablePluginCollectionTest into DefaultLazyPluginCollectionTest

Issue #2407733 by mortendk, rteijeiro, sivaji@knackforge.com: Remove classes from system templates i*.html.twig

Issue #2420107 by alexpott: Determine which config entities can be fixed and which will be deleted when a dependency is removed

Issue #2383413 by larsmw, Cottser, alvar0hurtad0: Remove file_exists() when registering namespaces for Twig template paths

Issue #2318437 by Wim Leers, Gábor Hojtsy, geertvd: Replace the hardcoded langcode key on blocks with the 'language' cache context

Issue #2091337 by genjohnson, no_angel, jhodgdon, ifrik, thijsvdanker, theMusician, amitgoyal: Update hook_help for Image module

Issue #2425759 by andypost, jhodgdon: SearchQuery lacks preExecute(), making countQuery() run even when there are problems in prepare step

Issue #1807160 by Mile23, martin107, ParisLiakos, Lars Toomre: Add missing type hinting to Aggregator module docblocks

Issue #2418031 by BassistJimmyJam, pwolanin, tadityar, Wim Leers: Remove MenuLinkContentForm::doValidate() since the logic was moved to LinkWidget::validateUriElement()

Issue #2407745 by mortendk, rteijeiro, sivaji@knackforge.com: Remove classes from system templates t*.html.twig

Issue #2395627 by tstoeckler, Leksat, webflo, Gábor Hojtsy: Do not remove 0 from config translation data