Merge pull request #549 from nsendetzky/master

Makes stock retrieval and CSS more robust, removes layout directory name
Show currently selected language
Handle unknown language code
Rename id to index and predefine
Merge pull request #550 from cookiekiller/show_selected_language

Shows the currently selected language
Merge branch 'master' of https://github.com/Arcavias/arcavias-core
Fixes wrong parameter in set() method for decorators