Manual shutdown support in Angular2

[qdrk]

A typical use case is instead of letting angular framework takes over the whole app, only certain parts of the app uses angular. So it would be nice if angular is self-contained, or at least have a clear boundary when it interacts with global component like location and how to dis-entangle them. See here for a discussion in Angular 1 tracking #1537

[Narretz]

Please post in the angular/angular repo. Thanks!