Add translate client code (can't get tranlate API to work!)

So I had this in this state by late last night.  I spent a while then and a bit today trying to get the Google Translate API to work.  I signed up for billing on multiple accounts and enabled a bunch of stuff but I can't get it to do anything but return a 403 (forbidden).

I finally decided to give up but I figured I might as well give you a pull req for the last bit of code to make this work if you can figure out how to get a working API key.

So, this *should* all work, you'd just need to do this:

1. Get an account with a working GT API key (apparently the hard part).
2. Add this to your ~/.api_keys file:
GOOGLE_API_KEY=<your working key here>
3. Modify getTranslationForString:... in TranslateClient to return just the translated string (or modify the calling code in ChatViewController.m to manipulate the returned object.
4. Profit!

Or alternatively try out one of the other translate APIs that are free.

I will probably try to mess with this a bit more but it will probably be after I get back to Atlanta (mid Aug).  Regardless, thanks for letting me share your project and I'd love to see it in the App Store!