message: Removed scene now context isolated
  The scene for the Shared Element doesn't change during navigation because each Scene has its own NavigationContext. Removed scene === crumbs.length check because its always true
diff: @@ -5,32 +5,28 @@ import { SharedElementProps } from './Props';
  class SharedElement extends React.Component<SharedElementProps, any> {
  private ref: HTMLElement;
  - private scene: number;
  - constructor(props) {
  - super(props);
  - this.scene = this.props.stateNavigator.stateContext.crumbs.length;
  - this.register = this.register.bind(this);
  - }
  componentDidMount() {
  this.register();
  }
  componentDidUpdate(prevProps) {
  - this.props.sharedElementRegistry.unregisterSharedElement(this.scene, prevProps.name);
  + var {stateNavigator, sharedElementRegistry} = this.props;
  + var scene = stateNavigator.stateContext.crumbs.length;
  + sharedElementRegistry.unregisterSharedElement(scene, prevProps.name);
  this.register();
  }
  componentWillUnmount() {
  - this.props.sharedElementRegistry.unregisterSharedElement(this.scene, this.props.name);
  + var {stateNavigator, sharedElementRegistry} = this.props;
  + var scene = stateNavigator.stateContext.crumbs.length;
  + sharedElementRegistry.unregisterSharedElement(scene, this.props.name);
  }
  register() {
  - var {crumbs, oldUrl} = this.props.stateNavigator.stateContext;
  - if (this.scene === crumbs.length || (oldUrl && this.scene === oldUrl.split('crumb=').length - 1)) {
  - var {unshare, name, data, sharedElementRegistry} = this.props;
  + var {unshare, name, data, stateNavigator, sharedElementRegistry} = this.props;
  + var scene = stateNavigator.stateContext.crumbs.length;
  if (!unshare) {
  if (this.ref)
  - sharedElementRegistry.registerSharedElement(this.scene, name, this.ref, data);
  + sharedElementRegistry.registerSharedElement(scene, name, this.ref, data);
  } else {
  - sharedElementRegistry.unregisterSharedElement(this.scene, name);
  - }
  + sharedElementRegistry.unregisterSharedElement(scene, name);
  }
  }
  render() {
  