Refactor of PolymerExpressions. Adds "as" expressions.

pkg/polymer_expressions/test/bindings_test.dart

Index: pkg/polymer_expressions/test/bindings_test.dart
diff --git a/pkg/polymer_expressions/test/bindings_test.dart b/pkg/polymer_expressions/test/bindings_test.dart
index 209012d17a3f84214202cfec555a8f0e548f9085..36c66edad98ef59dc038d66da63915b6b606d966 100644
--- a/pkg/polymer_expressions/test/bindings_test.dart
+++ b/pkg/polymer_expressions/test/bindings_test.dart
@@ -12,11 +12,14 @@ import 'package:observe/observe.dart';
 import 'package:observe/src/dirty_check.dart' show dirtyCheckZone;
 import 'package:polymer_expressions/polymer_expressions.dart';
 import 'package:template_binding/template_binding.dart' show templateBind;
-import 'package:unittest/html_config.dart';
+//import 'package:unittest/html_config.dart';
+import 'package:unittest/html_enhanced_config.dart';

[Jennifer Messerly, 2014/03/17 23:10:08]

FWIW. I have a very hard time debugging failures using enchanced config. It can
obscure information about failures. I've changed tests to use raw html_config
wherever possible.

[justinfagnani, 2014/04/24 00:26:13]

Done, but I usually have to solo a test and disable the tearDown to debug it
anyway, so I didn't care much about the configuration.

+
 import 'package:unittest/unittest.dart';
 
 main() => dirtyCheckZone().run(() {
-  useHtmlConfiguration();
+  useHtmlEnhancedConfiguration();
+//  useHtmlConfiguration();
 
   group('bindings', () {
     var stop = null;