message: Checked state and data instead of url
  Urls can mismatch even if data's the same because no guarantee of order of url parameters
diff: @@ -50,10 +50,15 @@ class Scene extends React.Component<NavigationMotionProps, NavigationMotionState
  }
  willNavigate({crumb: targetCrumb}) {
  var {crumb, navigationEvent} = this.props;
  - if (targetCrumb === crumb) {
  var {crumbs} = navigationEvent.stateNavigator.stateContext;
  - var {nextCrumb} = this.state.navigationEvent.stateNavigator.stateContext;
  - if (crumb < crumbs.length && crumbs[crumb].crumblessUrl !== nextCrumb.crumblessUrl) {
  + if (targetCrumb === crumb && crumb < crumbs.length) {
  + var {state: latestState, data: latestData} = crumbs[crumb];
  + var {state, data} = this.state.navigationEvent.stateNavigator.stateContext;
  + var unchanged = state === latestState && data.length === latestData.length;
  + for(var key in data) {
  + unchanged = unchanged && data[key] === latestData[key];
  + }
  + if (!unchanged) {
  var stackNavigationEvent = Scene.createNavigationEvent(navigationEvent, crumbs, crumb);
  this.setState({navigationEvent: stackNavigationEvent});
  }
  