Remove old isolate API and update all code in the repository to use

tests/standalone/io/echo_server_stream_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Echo server test program to test socket streams.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 #import("dart:io");
 #import("dart:isolate");
 #source("testing_server.dart");
 
 class EchoServerGame {
 
   static final MSGSIZE = 10;
   static final MESSAGES = 100;
   static final FIRSTCHAR = 65;
 
   EchoServerGame.start()
       : _receivePort = new ReceivePort(),
         _sendPort = null,
         _buffer = new List<int>(MSGSIZE),
         _messages = 0 {
     for (int i = 0; i < MSGSIZE; i++) {
       _buffer[i] = FIRSTCHAR + i;
     }
-    new EchoServer().spawn().then((SendPort port) {
-      _sendPort = port;
-      start();
-    });
+    _sendPort = spawnFunction(startEchoServer);
+    start();
   }
 
   void sendData() {
 
     void errorHandler(Exception e) {
       Expect.fail("Socket error $e");
     }
 
     void connectHandler() {
 
@@ skipping 84 matching lines @@
 
   int _port;
   ReceivePort _receivePort;
   SendPort _sendPort;
   Socket _socket;
   List<int> _buffer;
   int _messages;
 }
 
 
+void startEchoServer() {
+  var server = new EchoServer();
+  port.receive(server.dispatch);
+}
+
+
 class EchoServer extends TestingServer {
 
   static final int MSGSIZE = EchoServerGame.MSGSIZE;
 
   void onConnection(Socket connection) {
     InputStream inputStream;
     List<int> buffer = new List<int>(MSGSIZE);
     int offset = 0;
 
     void dataReceived() {
@@ skipping 19 matching lines @@
 
     inputStream = connection.inputStream;
     inputStream.onData = dataReceived;
     connection.onError = errorHandler;
   }
 }
 
 main() {
   EchoServerGame echoServerGame = new EchoServerGame.start();
 }