Remove .Interfaces from the namespace in Microsoft.AspNet.Http.Interfaces

[davidfowl]

[davidfowl]

We should do this as part of the API cleanup. Should we leave it as Http (that's actually cleaner) or add .Features back?

/cc @glennc @muratg @Tratcher

[Tratcher]

How is Http.Features any better than Http.Interfaces? By the convention it would be Http.Features in a package called Http.Features.Interfaces.

[Praburaj]

d5e1b19