Remove more libraries directives from server

pkg/analysis_server/lib/src/services/completion/completion_core.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 analysis_server.src.services.completion.completion_core;
-
 import 'package:analysis_server/src/ide_options.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart';
 import 'package:analysis_server/src/services/completion/completion_performance.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
  * The information about a requested list of completions.
  */
@@ skipping 55 matching lines @@
     _aborted = true;
   }
 
   @override
   void checkAborted() {
     if (_aborted) {
       throw new AbortCompletion();
     }
   }
 }