GUI does not render non-English characters

We are currently using a custom font, that only contains English characters. A good solution would be to enable using the original MW font (and in doing so bypassing most localisation problems). This would need to be optional though.

If that is not possible, we need to find a better font.

Note: The severity is set to minor, because for now users of non-English MW can easily replace the font with something that supports their language.

(RM-3 from redmine: created on 2011-08-06 by Lukasz Gromanowski, , closed on 2011-08-19 by Lukasz Gromanowski)