Content Negotiation need to return 400 Bad Request \ 415 unsupported media type

[NTaylorMullen]

In the past with WebAPI, we'd throw HttpResponseException with the right status code set and something in the pipeline would interpret it correctly. We need to figure out how to do this with formatters.

| 159 | 10317 | Reported By: Pranav K |

[yishaigalatzer]

Need more discussion around is this supposed to return 406 or 415.

[yishaigalatzer]

https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNet.Mvc.ModelBinding/Formatters/TempInputFormatterProvider.cs#L34