Merge remote-tracking branch 'origin/8.x' into 8.x-file-config

core/MAINTAINERS.txt

core/includes/ajax.inc

core/includes/bootstrap.inc

core/includes/common.inc

core/includes/database/database.inc

core/includes/database/query.inc

core/includes/install.core.inc

core/includes/install.inc

core/includes/pager.inc

core/includes/registry.inc

core/includes/tablesort.inc

core/lib/Drupal/Core/Database/Connection.php

...ib/Drupal/Core/Database/ConnectionNotDefinedException.php

core/lib/Drupal/Core/Database/Database.php

core/lib/Drupal/Core/Database/DatabaseException.php

core/lib/Drupal/Core/Database/Driver/mysql/Connection.php

core/lib/Drupal/Core/Database/Driver/mysql/Delete.php

core/lib/Drupal/Core/Database/Driver/mysql/Insert.php

core/lib/Drupal/Core/Database/Driver/mysql/Install/Tasks.php

core/lib/Drupal/Core/Database/Driver/mysql/Merge.php