I rethought this part after our Chat in IRC.

I think its not a good idea to use a dummy router here, since the layer which get's exposed here and the method `match` called later on are not part of the public API. And this will lead to potential work on this part every time express changes this implementation. I think it would be better to get a extra defined router here, which we can use to handle the permalink urls. What do you think?

This router can also be used to have named routes and [param transformation logic](http://expressjs.com/4x/api.html#router.param).

[See my comment in the PR.](https://github.com/TryGhost/Ghost/pull/2603#issuecomment-42139395)