message: Prevented update if not current scene
diff: @@ -14,6 +14,11 @@ class Scene extends React.Component {
  var {state, crumbs} = navigationEvent.stateNavigator.stateContext;
  return (state && crumbs.length === crumb) ? {navigationEvent} : null;
  }
  + shouldComponentUpdate() {
  + var {crumb, navigationEvent} = props;
  + var {state, crumbs} = navigationEvent.stateNavigator.stateContext;
  + return state && crumbs.length === crumb;
  + }
  render() {
  var {navigationEvent} = this.state;
  if (!navigationEvent) return null;
  