Fixing modelfactory and adding gzip encoding

Hi josh,

I mentioned this on the mailing list: Here's a tiny patch that fixes the built in status parser so people can actually subclass the user model.

I also added some lines to send "Accept-encoding": "gzip". I tested this briefly: it works and saves a lot of bandwidth. The only stain might be that I add the encoding in APIMethod's __init__ - you may prefer to set it in a different place, but that's merely a question of style.

Cheers,
Pascal