Initial commit of Dart transformer to generate constructor stubs, see https://github.com/angular/an…

modules/angular2/src/transform/traversal.dart

+library angular2.src.transform;
+
 import 'package:analyzer/src/generated/element.dart';
 import 'package:path/path.dart' as path;
 
 import 'annotation_processor.dart';
 
 class ImportTraversal {
   final AnnotationMatcher _annotationMatcher;
 
   ImportTraversal(this._annotationMatcher);
 
@@ skipping 80 matching lines @@
       }
 
       // And finally compare based on the relative uri if both are file paths.
       var aUri = path.relative(a.source.uri.path,
           from: path.dirname(library.source.uri.path));
       var bUri = path.relative(b.source.uri.path,
           from: path.dirname(library.source.uri.path));
       return aUri.compareTo(bUri);
     })).map((import) => import.importedLibrary);
 }