feat(bootstrap): remove the need for explicit reflection setup in bootstrap code

BREAKING CHANGES:

Dart applications and TypeScript applications meant to transpile to Dart must now
import `package:angular2/bootstrap.dart` instead of `package:angular2/angular2.dart`
in their bootstrap code. `package:angular2/angular2.dart` no longer export the
bootstrap function. The transformer rewrites imports of `bootstrap.dart` and calls
to `bootstrap` to `bootstrap_static.dart` and `bootstrapStatic` respectively.

modules/angular2/angular2.dart

@@ -0,0 +1,8 @@
+library angular2;
+
+/**
+ * An all-in-one place to import Angular 2 stuff.
+ *
+ * This library does not include `bootstrap`. Import `bootstrap.dart` instead.
+ */
+export 'package:angular2/angular2_exports.dart';