React.js should only export the isomorphic stuff. No dependencies on DOM. The secret export stuff is only for the browserify package so we should just do a special case file here:

https://github.com/facebook/react/blob/master/grunt/config/browserify.js#L66

Rename `React.js` -> `ReactBrowserify.js` and `ReactIsomorphic.js` -> `React.js`.

That way we don't take on the dom dependencies in the npm package. Will help with React Native unification.

'use strict';
module.exports = require('./ReactIsomorphic');