Move React Core Integration to a Dependency

Summary:Adding the react native renderer dependency and various fixes to support React 15.

Don't use dispatchID for touchableHandleResponderGrant

This callback argument was removed because "IDs" no longer exist. Instead, we'll
use the tag from the event target.

The corresponding PR on React Core is: facebook/react#6338

Reviewed By: spicyj

Differential Revision: D3159788

fb-gh-sync-id: 60e5cd2aa0af69d83fcdac3dfde0a85a748cb7b9
fbshipit-source-id: 60e5cd2aa0af69d83fcdac3dfde0a85a748cb7b9

blacklist.js

@@ -14,8 +14,6 @@ var path = require('path');
 // modulePathIgnorePatterns.
 var sharedBlacklist = [
   /node_modules[/\\]react[/\\]dist[/\\].*/,
-  'node_modules/react/lib/React.js',
-  'node_modules/react/lib/ReactDOM.js',
 
   'downstream/core/invariant.js',