User:Liangent/wb-lang/dev

Req

 * Clean up language codes first (eg zh-classical => lzh, zh-yue => yue and disable some codes)
 * Site link table (see above)

API

 * For all actions accepting &languages=:
 * When &languages=zh-cn is wanted but zh-cn is not there:
 *  if there's zh-tw and en in known labels ('something' is guaranteed to be in zh-cn, by Language converter)
 *  if there's only en in known labels ('something' is in English)
 * Aliases: convert-fallbacks are added, but plain fallbacks are not added