Update pub to use new import syntax.

utils/pub/entrypoint.dart

Index: utils/pub/entrypoint.dart
diff --git a/utils/pub/entrypoint.dart b/utils/pub/entrypoint.dart
index be51ca7c63fbb57c989609b356a9264223c36211..7a82a63bbb59e80d40e9dae58806bf0a54c2eeea 100644
--- a/utils/pub/entrypoint.dart
+++ b/utils/pub/entrypoint.dart
@@ -2,16 +2,16 @@
 // 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');
+library entrypoint;
 
-#import('io.dart');
-#import('lock_file.dart');
-#import('package.dart');
-#import('root_source.dart');
-#import('system_cache.dart');
-#import('version.dart');
-#import('version_solver.dart');
-#import('utils.dart');
+import 'io.dart';
+import 'lock_file.dart';
+import 'package.dart';
+import 'root_source.dart';
+import 'system_cache.dart';
+import 'version.dart';
+import 'version_solver.dart';
+import 'utils.dart';
 
 /**
  * Pub operates over a directed graph of dependencies that starts at a root