[ticket/10549] Adds language variables

PHPBB3-10549
Merge pull request #2100 from Crizz0/ticket/10549

[ticket/10549] Adds language variables to Error messages MODULE...
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/10549] Adds language variables

Conflicts:
	phpBB/includes/functions_module.php