isolates refactor: this change introduces 'dart:isolate' as a library. This is a

lib/isolate/isolate_compiler.dart

+// Copyright (c) 2011, 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.
+
+
+// Dart isolate's API for the dartc compiler (only used for type checking in the
+// dart editor, but not for code generation).
+#library("dart:isolate");
+
+#source("isolate_api.dart");
+
+class _IsolateFactory {
+
+  factory Isolate2.fromCode(Function topLevelFunction) {
+    throw new NotImplementedException();
+  }
+
+  factory Isolate2.fromUri(String uri) {
+    throw new NotImplementedException();
+  }
+}
+
+class _IsolateNatives {
+  static Future<SendPort> spawn(Isolate isolate, bool isLight) {
+    throw new NotImplementedException();
+  }
+}
+
+class ReceivePortFactory {
+
+  factory ReceivePort() {
+    throw new NotImplementedException();
+  }
+
+  factory ReceivePort.singleShot() {
+    throw new NotImplementedException();
+  }
+}