Provide response information for get function

[Zappatta]

Currently, calling the batch function and issuing a batch requets, will yield an array of results as received from facebook. This array will include the response code and headers for each request in the batch.

However, calling the get function will only yield the response body, and will omit the headers and status code of the response. This information may actually be useful and needed by users of the lib. For example, for for rate limited as mentioned in #136
So callbacks for the get function should also receive more info about the response. At least the headers and status code.