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.