Still the file was .r2skin-addon which is not in the helpfile.
No, but it is explained on the languages page. See my post above here: 'From the website languagepage'...
Btw, shouldn't this file be part of the main distribution as well ? It's not too big.
I think the english interface is the most used one, so distributing all the languages files and the translated skin is a bit overdone. If a user wants Rainlendar in another language, he/she downloads/installs the language file and the translated skin. That's simple.