Added ring.util.request namespace and header-seq func

@@ -0,0 +1,10 @@
+(ns ring.util.request
+  "Parse and interpret Ring requests"
+  (:require [clojure.string :as str]))
+
+(defn header-seq
+  "Returns seq of values for the specified header. Multiple values can be
+  encoded in one header key using a comma as a separator."
+  [request key]
+  (-> (get-in request [:headers (name key)])
+      (str/split #"\s*,\s*")))