Break up another large file

pkg/analyzer/lib/source/error_processor.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 analyzer.source.error_processor;
 
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
+import 'package:analyzer/src/task/options.dart'
+    show CONFIGURED_ERROR_PROCESSORS;
 import 'package:analyzer/src/task/options.dart';
 import 'package:yaml/yaml.dart';
 
 /// String identifiers mapped to associated severities.
 const Map<String, ErrorSeverity> severityMap = const {
   'error': ErrorSeverity.ERROR,
   'info': ErrorSeverity.INFO,
   'warning': ErrorSeverity.WARNING
 };
 
@@ skipping 105 matching lines @@
     ErrorCode errorCode = error.errorCode;
     if (errorCode is StaticTypeWarningCode) {
       return true;
     }
     if (errorCode is StaticWarningCode) {
       return errorCode.isStrongModeError;
     }
     return false;
   }
 }