Use Utf8Stream for http Streams with utf8 encoding

lib/http.js

@@ -9,6 +9,7 @@ function debug (x) {
 
 var sys = require('sys');
 var net = require('net');
+var Utf8Stream = require('utf8_stream').Utf8Stream;
 var events = require('events');
 var Buffer = require('buffer').Buffer;
 
@@ -91,6 +92,8 @@ var parsers = new FreeList('parsers', 1000, function () {
     var enc = parser.incoming._encoding;
     if (!enc) {
       parser.incoming.emit('data', b.slice(start, start+len));
+    } else if (this._decoder) {
+      this._decoder.write(pool.slice(start, end));
     } else {
       var string = b.toString(enc, start, start+len);
       parser.incoming.emit('data', string);
@@ -198,6 +201,15 @@ IncomingMessage.prototype.setBodyEncoding = function (enc) {
 IncomingMessage.prototype.setEncoding = function (enc) {
   // TODO check values, error out on bad, and deprecation message?
   this._encoding = enc.toLowerCase();
+  if (this._encoding == 'utf-8' || this._encoding == 'utf8') {
+    this._decoder = new Utf8Stream();
+    this._decoder.onString = function(str) {
+      this.emit('data', str);
+    };
+  } else if (this._decoder) {
+    delete this._decoder;
+  }
+
 };
 
 IncomingMessage.prototype.pause = function () {