Support JSON-derived media types

By default, Hapi returns a `415: Unsupported Media Type` error if you try and send a content-type header that is a json derived media type.

Examples include the media types for various hypermedia specs and json patch:

* `application/json-patch+json`
* `application/vnd.collection+json`
* `application/hal+json`
* `application/vnd.siren+json`

This PR will go ahead and json parse these, as well as the more typical `application/json`.