Restructure the public API for server

pkg/analysis_server/lib/src/edit/edit_domain.dart

 // Copyright (c) 2014, 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 edit.domain;
 
 import 'dart:async';
 
-import 'package:analysis_server/edit/assist/assist_core.dart';
-import 'package:analysis_server/edit/fix/fix_core.dart';
+import 'package:analysis_server/plugin/edit/assist/assist_core.dart';
+import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/collections.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/assist.dart';
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analysis_server/src/services/correction/organize_directives.dart';
 import 'package:analysis_server/src/services/correction/sort_members.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
@@ skipping 709 matching lines @@
     }
     return new RefactoringStatus();
   }
 }
 
 /**
  * [_RefactoringManager] throws instances of this class internally to stop
  * processing in a manager that was reset.
  */
 class _ResetError {}