Get rid of all the library tags.

lib/src/base64.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 crypto.base64;
-
 import 'dart:convert';
 
 import 'base64/decoder.dart';
 import 'base64/encoder.dart';
 
 /// An instance of the default implementation of [Base64Codec].
 ///
 /// This provides convenient access to most common Base64 use-cases.
 const Base64Codec BASE64 = const Base64Codec();
 
@@ skipping 58 matching lines @@
         encodePaddingCharacter: encodePaddingCharacter).convert(bytes);
   }
 
   Base64Encoder get encoder => new Base64Encoder(
       urlSafe: _urlSafe,
       addLineSeparator: _addLineSeparator,
       encodePaddingCharacter: _encodePaddingCharacter);
 
   Base64Decoder get decoder => const Base64Decoder();
 }