* canActivate(params, routeConfig, navigationInstruction) : Implement this hook if you want to control whether or not your view-model can be navigated to. Return a boolean value, a promise for a boolean value, or a navigation command.
* activate(params, routeConfig, navigationInstruction) : Implement this hook if you want to perform custom logic just before your view-model is displayed. You can optionally return a promise to tell the router to wait to bind and attach the view until after you finish your work.
* canDeactivate() : Implement this hook if you want to control whether or not the router can navigate away from your view-model when moving to a new route. Return a boolean value, a promise for a boolean value, or a navigation command.
* deactivate() : Implement this hook if you want to perform custom logic when your view-model is being navigated away from. You can optionally return a promise to tell the router to wait until after you finish your work.
