Add: support for nested pagination meta data

[DavidPhilip]

As the name states I needed to support this for a project I'm working on as the meta data for pagination doesn't necessarily have to lie in the root of the meta object.

Example:

{
  "authors": [
    {
      "id": "1",
      ...
    }
  ],
  "meta": {
    "pagination": {
      "total": 120,
      "count": 25,
      "per_page": 25,
      "current_page": 1,
      "total_pages": 5,
      "links": {
        "next": "http://..."
      }
    }
  }
}

The mapping would then be added to paramMapping for this example like this:

params.paramMapping = { meta: "pagination" };

I suppose I could write tests for this too if I have more time. Take your time, review the code and let me know how you want to continue.

Regards,
David