add initWebComponents

lib/src/static_initializer.dart

+// Copyright (c) 2014, 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.
+
+/// Static logic for initializing web_components. This assumes the entire app
+/// is reachable from the entry point.
+library web_components.src.static_initializer;
+
+import 'dart:async';
+import 'package:initialize/initialize.dart' as init;
+
+Future run({List<Type> typeFilter, init.InitializerFilter customFilter}) =>
+    init.run(typeFilter: typeFilter, customFilter: customFilter);