added plugin transformer which initializers can extend to do additional post-processing during tran…

lib/src/mirror_loader.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 initialize.mirror_loader;
 
 import 'dart:collection' show Queue;
 import 'dart:mirrors';
 import 'package:path/path.dart' as path;
 import 'package:initialize/initialize.dart';
 
@@ skipping 131 matching lines @@
           // TODO(jakemac): Support static class methods.
           throw _TOP_LEVEL_FUNCTIONS_ONLY;
         }
         annotatedValue = (declaration.owner as ObjectMirror)
             .getField(declaration.simpleName).reflectee;
       } else if (declaration is LibraryMirror) {
         var package;
         var filePath;
         Uri uri = declaration.uri;
         if (uri.scheme == 'file' || uri.scheme.startsWith('http')) {
-          filePath = path.url.relative(
-              uri.path, from: path.url.dirname(_root.uri.path));
+          filePath = path.url.relative(uri.path,
+              from: path.url.dirname(_root.uri.path));
         } else if (uri.scheme == 'package') {
           var segments = uri.pathSegments;
           package = segments[0];
           filePath = path.url.joinAll(segments.getRange(1, segments.length));
         } else {
           throw new UnsupportedError('Unsupported uri scheme ${uri.scheme} for '
               'library ${declaration}.');
         }
         annotatedValue =
             new LibraryIdentifier(declaration.qualifiedName, package, filePath);
@@ skipping 21 matching lines @@
     return true;
   }
 }
 
 final _TOP_LEVEL_FUNCTIONS_ONLY = new UnsupportedError(
     'Only top level methods are supported for initializers');
 
 final _UNSUPPORTED_DECLARATION = new UnsupportedError(
     'Initializers are only supported on libraries, classes, and top level '
     'methods');