Integrating language code "ase"

Honestly, I have no idea where the 'American' description came from. I have changed it to American sign language for now. That does however not mean that we (can) support it for now.

You have sent me an e-mail with a lot of questions and ideas that I will most definitely reply to soonish. I think we need to look into proper support for (A)SL in MediaWiki before trying to support it in here, and before any localisations in other products than MediaWiki proper should be done -- it's just too bleeding edge at the moment IMO.