* Add an UnsupportedContentType to the ModelState dictionary when no formatter can read the body.
* Add a filter to the pipeline that searches for that specific exception and transforms the response into 415.
- #3612 subpart 2 of 2
- merge `ActionConstraintsWebSite`, `AntiforgeryTokenWebSite` and `ContentNegotiationWebSite` into `BasicWebSite`
- remove tests depending on `ErrorReporterMiddleware` in merged sites; not used in `BasicWebSite`
- delete `CompositeViewEngineWebSite`, `Microsoft.AspNet.Mvc.ViewEngines.CompositeViewEngineTest` covers cases
- delete `CorsMiddlewareWebsite`, soon to be in Cors repo (see aspnet/CORS#57)
- remove `SendFileMiddleware` from FilesWebSite, unused there
Steve Sanderson
jacalvar
N. Taylor Mullen
Doug Bunting