wp-config.php:
/**
* WordPress Localized Language, defaults to English.
*
* Change this to localize WordPress. A corresponding MO file for the chosen
* language must be installed to wp-content/languages. For example, install
* de_DE.mo to wp-content/languages and set WPLANG to 'de_DE' to enable German
* language support.
*/
define('WPLANG', 'de_DE');
This part does not seem to work with the “–wpsubdir” option. It works fine with a single site.
Also, I was wondering when and how this feature is incorporated: