Remove more libraries directives from server

pkg/analysis_server/lib/src/services/dependencies/reachable_source_collector.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.
 
-library services.dependencies.reachable_source_collector;
-
 import 'dart:collection';
 
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/task/dart.dart';
 
 /// Collects reachable sources.
 class ReachableSourceCollector {
   final Map<String, List<String>> _sourceMap =
       new HashMap<String, List<String>>();
@@ skipping 26 matching lines @@
     List<Source> sources = <Source>[];
     sources.addAll(context.computeResult(source, IMPORTED_LIBRARIES));
     sources.addAll(context.computeResult(source, EXPORTED_LIBRARIES));
 
     _sourceMap[sourceUri] =
         sources.map((source) => source.uri.toString()).toList();
 
     sources.forEach((s) => _addDependencies(s));
   }
 }