message: Un/registerd when un/share events fire
diff: @@ -8,15 +8,31 @@ class SceneProxy extends React.Component<SceneProxyProps> {
  private sceneEl: React.RefObject<HTMLDivElement>;
  constructor(props) {
  super(props);
  + this.share = this.share.bind(this);
  + this.unshare = this.unshare.bind(this);
  this.sceneEl = React.createRef();
  }
  componentDidMount() {
  + this.sceneEl.current.addEventListener("share", this.share);
  + this.sceneEl.current.addEventListener("unshare", this.unshare);
  var {crumb, app: App} = this.props;
  ReactDOM.render(<App crumb={crumb} />, this.sceneEl.current);
  }
  componentWillUnmount() {
  + this.sceneEl.current.removeEventListener("share", this.share);
  + this.sceneEl.current.removeEventListener("unshare", this.unshare);
  ReactDOM.unmountComponentAtNode(this.sceneEl.current);
  }
  + share(e) {
  + var {target, detail} = e;
  + var {crumb, sharedElementRegistry} = this.props;
  + sharedElementRegistry.registerSharedElement(crumb, name, target, detail.data);
  + }
  + unshare(e) {
  + var {detail} = e;
  + var {crumb, sharedElementRegistry} = this.props;
  + sharedElementRegistry.unregisterSharedElement(crumb, detail.name);
  + }
  render() {
  return (
  <div ref={this.sceneEl} />
  