EZP-21125: implement slots for clearing LS langauge cache
EZP-21125: configure slots for clearing LS langauge cache
EZP-21125: fixed null return value being cached
Merge pull request #512 from ezsystems/fix-EZP-21125-language-not-visible

Fix EZP-21125: (PAPI) Created language is only shown in admin interface after creating a new language