Issue #2379683 by Gábor Hojtsy: Fix configuration schema issues in contact (indirectly user and system) modules
Issue #2380573 by tibbsa: Add @return $this to ConfigInstallerInterface::setSynching
Issue #2030661 by lokeoke, lokapujya, larowlan, dinarcon, daffie, izus, Ivan Zugec: Expand Tour with methods