Break up another large file

pkg/analyzer/lib/src/error.dart

 // Copyright (c) 2013, 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 analyzer.src.error;
 
 import 'dart:collection';
 
-import 'package:analyzer/src/generated/error.dart';
+import 'package:analyzer/error/error.dart';
 
 /// The maximum line length when printing extracted source code when converting
 /// an [AnalyzerError] to a string.
 final _MAX_ERROR_LINE_LENGTH = 120;
 
 /// A wrapper around [AnalysisError] that provides a more user-friendly string
 /// representation.
 class AnalyzerError implements Exception {
   final AnalysisError error;
 
@@ skipping 69 matching lines @@
       : this(errors.map((e) => new AnalyzerError(e)));
 
   /// The errors in this collection.
   List<AnalyzerError> get errors =>
       new UnmodifiableListView<AnalyzerError>(_errors);
 
   String get message => toString();
   @override
   String toString() => errors.join("\n");
 }