Revert "url: significantly improve the performance of the url module"

This reverts commit 3fd7fc4.

It was agreed that this change contained too much potential ecosystem
breakage, particularly around the inability to `delete` properties off a
`Url` object. It may be re-introduced for a later release, along with
better work on ecosystem compatibility.

PR-URL: #1602
Reviewed-By: Mikeal Rogers <mikeal.rogers@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Forrest L Norvell <forrest@npmjs.com>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Isaac Z. Schlueter <i@izs.me>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

lib/_http_client.js

@@ -20,7 +20,7 @@ function ClientRequest(options, cb) {
   OutgoingMessage.call(self);
 
   if (typeof options === 'string') {
-    options = url.parse(options).toJSON();
+    options = url.parse(options);
   } else {
     options = util._extend({}, options);
   }

lib/https.js

@@ -107,7 +107,7 @@ exports.Agent = Agent;
 
 exports.request = function(options, cb) {
   if (typeof options === 'string') {
-    options = url.parse(options).toJSON();
+    options = url.parse(options);
   } else {
     options = util._extend({}, options);
   }