Add multilingual support to the module

Update the code to resolve "included" key data correctly for multilingual sites, please review.

I have reviewed and tested the proposed feature, looks good to me. Marking as RTBC.

Hello /u/alexbukach,

Can you please check this, It'll be better if it is merged.

This will still fail if you make a request in the default language, that does includes the language prefix (assuming you set one).
Although the prefix is optional for the default language, you can perfectly set one and then make a request with it as well. In fact, I find it to be more consistent.

In addition, the prefix is assumed to be 2 characters, but that isn't necessarily the case. It could be anything really.