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

tests/isolate/v2_unresolved_ports_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.
-
-// spawns multiple isolates and sends unresolved ports between them.
-#library('unresolved_ports');
-#import('dart:isolate');
-#import('../../lib/unittest/unittest.dart');
-
-// This test does the following:
-//  - main spawns two isolates: 'tim' and 'beth'
-//  - 'tim' spawns an isolate: 'bob'
-//  - main starts a message chain:
-//       main -> beth -> tim -> bob -> main
-//    by giving 'beth' a send-port to 'tim'.
-
-bethIsolate() {
-  port.receive((msg, reply) => msg[1].send(
-        '${msg[0]}\nBeth says: Tim are you coming? And Bob?', reply));
-}
-
-timIsolate() {
-  SendPort bob = spawnFunction(bobIsolate);
-  port.receive((msg, reply) => bob.send(
-        '$msg\nTim says: Can you tell "main" that we are all coming?', reply));
-}
-
-bobIsolate() {
-  port.receive((msg, reply) => reply.send(
-        '$msg\nBob says: we are all coming!'));
-}
-
-main() {
-  test('Message chain with unresolved ports', () {
-    ReceivePort port = new ReceivePort();
-    port.receive(expectAsync2((msg, _) {
-      expect(msg, equals('main says: Beth, find out if Tim is coming.'
-        '\nBeth says: Tim are you coming? And Bob?'
-        '\nTim says: Can you tell "main" that we are all coming?'
-        '\nBob says: we are all coming!'));
-      port.close();
-    }));
-
-    SendPort tim = spawnFunction(timIsolate);
-    SendPort beth = spawnFunction(bethIsolate);
-
-    beth.send(
-        // because tim is created asynchronously, here we are sending an
-        // unresolved port:
-        ['main says: Beth, find out if Tim is coming.', tim],
-        port.toSendPort());
-  });
-}