message: Shared context creation
diff: @@ -6,13 +6,14 @@ type SceneState = { context: { oldState: State, state: State, data: any, asyncDa
  class Scene extends React.Component<{ stateNavigator: AsyncStateNavigator }, SceneState> {
  constructor(props) {
  super(props);
  - var { stateNavigator } = this.props;
  - var { oldState, state, data, asyncData } = stateNavigator.stateContext;
  - this.state = { context: { oldState, state, data, asyncData, nextState: null, nextData: {}, stateNavigator } };
  + this.state = Scene.createContext(this.props.stateNavigator);
  }
  static getDerivedStateFromProps({ stateNavigator }, { context }) {
  if (stateNavigator.stateContext.crumbs.length !== context.stateNavigator.stateContext.crumbs.length)
  return null;
  + return Scene.createContext(stateNavigator);
  + }
  + static createContext(stateNavigator: AsyncStateNavigator) {
  var { oldState, state, data, asyncData } = stateNavigator.stateContext;
  return { context: { oldState, state, data, asyncData, nextState: null, nextData: {}, stateNavigator } };
  }
  