makemessages -l takes a locale name, not a language code.

Hi.  I'm new to translation in Django.  I read the docs for makemessage and had a lot of trouble getting translation on my web site to work properly.  It's only after a lot of messing around that I realised that makemessages should be passed a locale name not (as the docs say) a language code.

I added Indonesian as an example of where the locale code doesn't include a country code.  

I think no trac ticket needed, as there is no functionality change, and use of language code rather than locale name is a typo.