sort classes in dependency order, or load lazily if needed, fixes #78

test/sunflower/sunflower.html

Index: test/sunflower/sunflower.html
diff --git a/test/sunflower/sunflower.html b/test/sunflower/sunflower.html
index 321b12af8d4c67e07098081ffb07a6790a49349c..61aaf33f10bada9defa5fff1224605391788daa2 100644
--- a/test/sunflower/sunflower.html
+++ b/test/sunflower/sunflower.html
@@ -36,6 +36,7 @@
       var dom = { document: document };
     </script>
     <script src="../../lib/runtime/dart_runtime.js"></script>
+    <script src="../../lib/runtime/dart_core.js"></script>
     <script src="../codegen/expect/sunflower.js"></script>
     <script>sunflower.main();</script>
   </body>