Rename fletch -> dartino

tests/isolate/isolate_spawn_test.dart

 // Copyright (c) 2014, the Dartino 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.md file.
 
-import 'dart:fletch';
+import 'dart:dartino';
 
 import 'package:isolate/isolate.dart';
 import 'package:expect/expect.dart';
 
 void main() {
   Expect.equals(5, Isolate.spawn(simple).join());
 
   Expect.equals(3, Isolate.spawn(() => increment(2)).join());
   Expect.equals(5, Isolate.spawn(() => increment(4)).join());
 
@@ skipping 19 matching lines @@
   return x - y;
 }
 
 compileTimeError() {
   a b c;
 }
 
 throwError() {
   throw 'error';
 }