fixed 'Maintype was not text, image, or querystring' error, when wrong type of response

[ramusus]

No description provided.

[martey]

As I described in #281 (comment), the "Maintype was not text, image, or querystring" error message is a generic error.

It would help if you could describe the issue that this fixes (are you seeing API responses that are valid JSON but are being returned with a HTML content-type?) and provide code that triggers the error.

[martey]

I am closing this pull request since there hasn't been a response in 3 weeks. I'll still receive any comments submitted here through email, though.

[matnel]

It seems that if too much data is asked, Facebook returns text (i.e., no header information to say this is JSON):

{"error":{"code":1,"message":"Please reduce the amount of data you're asking for, then retry your request"}}

But I think the current PR tries to type all HTML content into JSON (which well... might fail badly).
Instead, there might be room for some try - catch kind of thing.