add a built-in default implementation for connect-middleware

lets not ask everybody to copy-paste this middleware.
lets user-code customise the augmented attribute name

index.js

@@ -102,6 +102,19 @@ function getClientIp(req) {
     return ipAddress;
 }
 
+/**
+ * Expose a default implemtation for a connect middleware
+ * 
+ * @options.attributeName - name of attribute to augment request object with
+ */
+getClientIp.mw = function(options) {
+    var attr = options.attributeName || "clientIp";
+    return function(req, res, next) {
+        req[attr] = requestIp.getClientIp(req); // on localhost > 127.0.0.1
+        next();
+    }
+};
+
 /**
  * Expose mode public functions
  */