Rename fletch -> dartino

tests/coroutine/fib_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:expect/expect.dart';
 
 main() {
   Expect.equals(1, fib(1));
   Expect.equals(1, fib(2));
   Expect.equals(2, fib(3));
   Expect.equals(144, fib(12));
   Expect.equals(75025, fib(25));
 }
 
 int fib(n) {
   if (n <= 2) return 1;
   return new Coroutine(fib)(n - 1)
        + new Coroutine(fib)(n - 2);
 }