Add tighter integration with Compojure

I thought it'd be quite nice to be able to define routes that are actually reusable without much duplicates, so I've added wrappers for functions compojure provides with named helpers on top:

```clj
;; Define with name users-index
(GET users-index "/users" {:keys [params]} ...)

;; And call, to generate users-index path:
(users-index-path)
```