Remove more libraries directives from server

pkg/analysis_server/lib/plugin/analysis/analyzed_files.dart

 // Copyright (c) 2015, 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.
 
 /**
  * Support for client code that extends the set of files being analyzed by the
  * analysis server.
  *
  * Plugins can contribute a list of file patterns. Any file whose path matches
  * one or more of the contributed patterns will be analyzed. The file patterns
  * are interpreted as glob patterns as defined by the 'glob' package.
  *
  * If a plugin is interested in analyzing a certain kind of file, it needs to
  * ensure that files of that kind will be analyzed. It should register a list of
  * file patterns by including code like the following in the plugin's
  * registerExtensions method:
  *
  *     @override
  *     void registerExtensions(RegisterExtension registerExtension) {
  *       ...
  *       registerExtension(
  *           ANALYZED_FILE_PATTERNS_EXTENSION_POINT_ID,
  *           ['*.yaml']);
  *       ...
  *     }
  */
-library analysis_server.plugin.analysis.analyzed_files;
-
 import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:plugin/plugin.dart';
 
 /**
  * The identifier of the extension point that allows plugins to cause certain
  * kinds of files to be analyzed. The object used as an extension must be a list
  * of strings. The strings are interpreted as glob patterns as defined by the
  * 'glob' package.
  */
 final String ANALYZED_FILE_PATTERNS_EXTENSION_POINT_ID = Plugin.join(
     ServerPlugin.UNIQUE_IDENTIFIER,
     ServerPlugin.ANALYZED_FILE_PATTERNS_EXTENSION_POINT);