Remove more libraries directives from server

pkg/analysis_server/lib/src/status/ast_writer.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.status.ast_writer;
-
 import 'dart:collection';
 
 import 'package:analysis_server/src/status/tree_writer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/src/dart/ast/ast.dart';
 
 /**
  * A visitor that will produce an HTML representation of an AST structure.
  */
@@ skipping 217 matching lines @@
     buffer.write('..');
     buffer.write(node.offset + node.length - 1);
     buffer.write(']');
     if (node.isSynthetic) {
       buffer.write(' (synthetic)');
     }
     buffer.write('</span>');
     buffer.write('<br>');
   }
 }