Get rid of all the library tags.

lib/src/source/git.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 pub.source.git;
-
 import 'dart:async';
 
 import 'package:path/path.dart' as path;
 import 'package:pub_semver/pub_semver.dart';
 
 import '../git.dart' as git;
 import '../io.dart';
 import '../log.dart' as log;
 import '../package.dart';
 import '../pubspec.dart';
@@ skipping 347 matching lines @@
         (result) => null);
   }
 
   /// Returns the path to the canonical clone of the repository referred to by
   /// [id] (the one in `<system cache>/git/cache`).
   String _repoCachePath(PackageRef ref) {
     var repoCacheName = '${ref.name}-${sha1(ref.description['url'])}';
     return path.join(systemCacheRoot, 'cache', repoCacheName);
   }
 }