With the reworking of configuratin setup, route configuration no longer
needs to be done in two separate steps. "compiling" the routes can now be
done as they are added.

Also, changed the way overrides are specified into a specific Override method
to make things consistent.
caching middleware is working on the new configuration approach
dispatcher is using the new configuration format
Context only knows about RequestIn (which is now called just Request).

RequestOut is only a concern of the upstram middleware now.

Also, fixed a bug with trying to return a nil saint response