Update pub to use new import syntax.

utils/pub/git_source.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('git_source');
+library git_source;
 
-#import('git.dart', prefix: 'git');
-#import('io.dart');
-#import('package.dart');
-#import('source.dart');
-#import('source_registry.dart');
-#import('utils.dart');
+import 'git.dart' as git;
+import 'io.dart';
+import 'package.dart';
+import 'source.dart';
+import 'source_registry.dart';
+import 'utils.dart';
 
 /**
  * A package source that installs packages from Git repos.
  */
 class GitSource extends Source {
   final String name = "git";
 
   final bool shouldCache = true;
 
   GitSource();
@@ skipping 194 matching lines @@
 
   /**
    * Returns [description] if it's a description, or [PackageId.description] if
    * it's a [PackageId].
    */
   _getDescription(description) {
     if (description is PackageId) return description.description;
     return description;
   }
 }