Don't send a HTTP/1.1 status line to HTTP/1.0 clients.

Fixes #1234.

lib/http.js

@@ -771,6 +771,8 @@ function ServerResponse(req) {
     this.useChunkedEncodingByDefault = false;
     this.shouldKeepAlive = false;
   }
+
+  this._httpVersion = req.httpVersion;
 }
 util.inherits(ServerResponse, OutgoingMessage);
 
@@ -831,8 +833,9 @@ ServerResponse.prototype.writeHead = function(statusCode) {
     headers = obj;
   }
 
-  var statusLine = 'HTTP/1.1 ' + statusCode.toString() + ' ' +
-                   reasonPhrase + CRLF;
+  var statusLine = 'HTTP/' + this._httpVersion
+                 + ' ' + statusCode.toString()
+                 + ' ' + reasonPhrase + CRLF;
 
   if (statusCode === 204 || statusCode === 304 ||
       (100 <= statusCode && statusCode <= 199)) {