We'll create a scoped service provider if the middleware that does it
isn't there.
We resolve all of our stuff from the scoped service provider, allowing
users to plug in any scoped things they want.
Ported UrlHelper to be a scoped service.
- Now that services are being flowed through the entire stack
we can nuke the csc service and always use the roslyn based compilation for views
- The RoslynCompilationService is still very much a prototype but it's a good
step to see what other services might may or may not need to flow.
- Removed the PhysicalFileSystem construction from Mvc itself. This will come from
the hosting layer and is newed up temporarily in the PathBasedViewFactory itself.