Merge remote-tracking branch 'origin/4.0' into develop

build/debian/source/lintian-overrides

dev/translation/sanity_check_en_langfiles.php

htdocs/admin/modules.php

htdocs/admin/perms.php

htdocs/api/admin/explorer.php

htdocs/contrat/index.php

htdocs/core/lib/files.lib.php

htdocs/index.php

htdocs/langs/en_US/admin.lang

htdocs/langs/en_US/install.lang

htdocs/langs/et_EE/install.lang