DAR-1063: Preparation for Special:CSS release

Special:CSS page is a simple editor with errors notifications and highlighting for Wikia.css file. It'll be accessible for wiki admins via Special:AdminDashboard. Except editing the page have also section of "CSS Updates" which are information pulled from blog posts on community wikis: EN, DE, ES, FR, IT, PL. If a user language isn't one from the group she'll get information from English community wiki.