Add Bob's path library to pub.

utils/pub/entrypoint.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.
 
 library entrypoint;
 
 import 'io.dart';
 import 'lock_file.dart';
 import 'package.dart';
 import 'root_source.dart';
 import 'system_cache.dart';
+import 'utils.dart';
 import 'version.dart';
 import 'version_solver.dart';
-import 'utils.dart';
 
 /**
  * Pub operates over a directed graph of dependencies that starts at a root
  * "entrypoint" package. This is typically the package where the current
  * working directory is located. An entrypoint knows the [root] package it is
  * associated with and is responsible for managing the "packages" directory
  * for it.
  *
  * That directory contains symlinks to all packages used by an app. These links
  * point either to the [SystemCache] or to some other location on the local
@@ skipping 254 matching lines @@
    * Creates a symlink to the `packages` directory in [dir] if none exists.
    */
   Future _linkSecondaryPackageDir(String dir) {
     var to = join(dir, 'packages');
     return exists(to).chain((exists) {
       if (exists) return new Future.immediate(null);
       return createSymlink(path, to);
     });
   }
 }