Added RU-language-files, provided by user shlack; converted to entities.
added missing Dutch language files for core modules
removed last remaining DE_du.php
fixed some errors in standard german language file
added new colloquially german language file (thanks to Michael Tenschert)
added kewyword id to all new files
Added default index.php to all folders to prevent directory spoofing
added language support to all integrated modules (except for news and form module)