Moved the route option resolver to  dedicated class "ResourceOptionInspector".
Added ContentNegotiator.
Updated composer, and added RouteOptions.
Finished "SerializationInspector".
Updated composer to have explicit dependencies.
Cleaned up the `RouteOptionInspectorTest`.
Cleaned up the `RouteOptionInspectorTest`.
Updated composer.lock.
Added namespace "Middleware".
Added more comments and cleanup.
More cleanup.
More cleanup.
More cleanup.