Adding Angular and dependent packages for testing

third_party/pkg/route_hierarchical/example/basic/example.dart

+library example;
+
+import 'dart:html';
+
+import 'package:logging/logging.dart';
+import 'package:route_hierarchical/client.dart';
+
+main() {
+  new Logger('')
+    ..level = Level.FINEST
+    ..onRecord.listen((r) => print('[${r.level}] ${r.message}'));
+
+  query('#warning').remove();
+
+  var router = new Router(useFragment: true);
+  router.root
+    ..addRoute(name: 'one', defaultRoute: true, path: '/one', enter: showOne)
+    ..addRoute(name: 'two', path: '/two', enter: showTwo);
+
+  query('#linkOne').attributes['href'] = router.url('one');
+  query('#linkTwo').attributes['href'] = router.url('two');
+
+  router.listen();
+}
+
+void showOne(RouteEvent e) {
+  print("showOne");
+  query('#one').classes.add('selected');
+  query('#two').classes.remove('selected');
+}
+
+void showTwo(RouteEvent e) {
+  print("showTwo");
+  query('#one').classes.remove('selected');
+  query('#two').classes.add('selected');
+}