Get rid of all the library tags.

lib/src/barback/pub_package_provider.dart

 // Copyright (c) 2013, 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.pub_package_provider;
-
 import 'dart:async';
 import 'dart:io';
 
 import 'package:barback/barback.dart';
 import 'package:path/path.dart' as path;
 
 import '../io.dart';
 import '../package_graph.dart';
 import '../preprocess.dart';
 import '../sdk.dart' as sdk;
@@ skipping 135 matching lines @@
     } else {
       var package = _graph.packages[packageName];
       return new Stream.fromIterable(
           package.listFiles(beneath: 'lib').map((file) {
         return new AssetId(packageName,
             path.toUri(package.relative(file)).toString());
       }));
     }
   }
 }