message: Made first param from instead of to
  Makes animation read better
  detail.getUnmountStyle = from => from ? 'slide_in' : 'slide_out';
diff: @@ -14,13 +14,13 @@ var addNavigateHandlers = (stateNavigator: StateNavigator | StateNavigator[]) =>
  var appKey = AppRegistry.getAppKeys()[0];
  if (oldCrumbs.length < crumbs.length) {
  var {state: nextState, data: nextData} = crumbs.concat(nextCrumb)[oldCrumbs.length + 1];
  - var exitAnim = oldState.getCrumbStyle && oldState.getCrumbStyle(true, oldData, oldCrumbs, nextState, nextData);
  - var enterAnim = state.getUnmountStyle && state.getUnmountStyle(false, data, crumbs);
  + var enterAnim = state.getUnmountStyle && state.getUnmountStyle(true, data, crumbs);
  + var exitAnim = oldState.getCrumbStyle && oldState.getCrumbStyle(false, oldData, oldCrumbs, nextState, nextData);
  } else {
  var nextCrumb = new Crumb(oldData, oldState, null, null, false);
  var {state: nextState, data: nextData} = oldCrumbs.concat(nextCrumb)[crumbs.length + 1];
  - var exitAnim = oldState.getUnmountStyle && oldState.getUnmountStyle(true, oldData, oldCrumbs);
  - var enterAnim = state.getCrumbStyle && state.getCrumbStyle(false, data, crumbs, nextState, nextData);
  + var enterAnim = state.getCrumbStyle && state.getCrumbStyle(true, data, crumbs, nextState, nextData);
  + var exitAnim = oldState.getUnmountStyle && oldState.getUnmountStyle(false, oldData, oldCrumbs);
  }
  NavigationModule.render(crumbs.length, tab, titles, appKey, enterAnim, exitAnim);
  }
  