Updated clojure.walk/walk to better handle MapEntry.

better-walk.clj

(defn walk [inner outer form]
  (cond
   (list? form) (outer (apply list (map inner form)))
   (instance? clojure.lang.IMapEntry form) (let [[k v] (map inner form)]
                                             (outer (clojure.lang.MapEntry. k v)))
   (seq? form) (outer (doall (map inner form)))
   (coll? form) (outer (into (empty form) (map inner form)))
   :else (outer form)))