I couldn't find `cs` in the keyboard `manifest.webapp`, nor the `keyboard/js/layout.js` from master... By double checking online I found that the country code `CS` is no longer in use (see [this wiki page](http://en.wikipedia.org/wiki/ISO_3166-2:CS)).

For the Czech Republic, `cz` is the correct country code -- and that seems to be present in `manifest.webapp` and `keyboard/js/layout.js`. I will leave it as is for now, feel free to file a separate bug regarding this if you think it should be addressed.