Add "point of interest" app for command-line testing of dart2js type information.

dart/tests/try/web/paste_content_rewriting_test.dart

 // Copyright (c) 2014, 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.
 
 library trydart.paste_test;
 
 import 'dart:html';
 import 'dart:async';
 
 import 'package:try/src/interaction_manager.dart' show
     InteractionManager;
 
 import 'package:try/src/ui.dart' show
     mainEditorPane,
     observer;
 
 import 'package:try/src/user_option.dart' show
     UserOption;
 
-import '../../pkg/expect/lib/expect.dart';
-import '../../pkg/async_helper/lib/async_helper.dart';
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
 
 const Map<String, String> tests = const <String, String> {
   '<span><p>//...</p>}</span>': '//...\n}',
   'someText': 'someText',
   '"\$"': '"<DIAGNOSTIC>\$</DIAGNOSTIC>"',
   '"\$\$"': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>"',
   '"\$\$4"': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>4"',
   '"\$\$4 "': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>4 "',
   '1e': '<DIAGNOSTIC>1e</DIAGNOSTIC>',
   'r"""\n\n\'"""': 'r"""\n\n\'"""',
@@ skipping 39 matching lines @@
 
   var interaction = new InteractionManager();
   mainEditorPane = new DivElement();
   document.body.append(mainEditorPane);
   observer = new MutationObserver(interaction.onMutation)
       ..observe(
           mainEditorPane, childList: true, characterData: true, subtree: true);
 
   asyncTest(runTests);
 }