NavigationExperimental

Summary:
A new API to unify internal navigation. Also addresses a highly-rated community 'pain': https://productpains.com/post/react-native/better-navigator-api-and-docs/

Offers the following improvements:

- Redux-style navigation logic is easy to reason about
- Navigation state can be easily saved and restored through refreshes
- Declarative navigation views can be implemented in native or JS
- Animations and gestures are isolated and now use the Animated library

public

Reviewed By: hedgerwang

Differential Revision: D2798048

fb-gh-sync-id: 88027ef9ead8a80afa38354252bc377455cc6dbb

Libraries/react-native/react-native.js

@@ -76,6 +76,7 @@ var ReactNative = {
   get LayoutAnimation() { return require('LayoutAnimation'); },
   get Linking() { return require('Linking'); },
   get LinkingIOS() { return require('LinkingIOS'); },
+  get NavigationExperimental() { return require('NavigationExperimental'); },
   get NetInfo() { return require('NetInfo'); },
   get PanResponder() { return require('PanResponder'); },
   get PixelRatio() { return require('PixelRatio'); },