Move 'react-dom-factories' require to getter module

**what is the change?:**
Moves `reauire('react-dom-factories')` to separate 'getter' module.

**why make this change?:**
To avoid circular dependency.

**test plan:**
WIP

Author: flarnie

src/addons/ReactDOMFactories.js

@@ -0,0 +1,14 @@
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactDOMFactories
+ */
+
+'use strict';
+
+module.export = require('react-dom-factories');

src/isomorphic/React.js

@@ -13,7 +13,7 @@
 
 var ReactBaseClasses = require('ReactBaseClasses');
 var ReactChildren = require('ReactChildren');
-var reactDOMFactories = require('react-dom-factories');
+var ReactDOMFactories = require('ReactDOMFactories');
 var ReactElement = require('ReactElement');
 var ReactPropTypes = require('ReactPropTypes');
 var ReactVersion = require('ReactVersion');
@@ -95,7 +95,7 @@ var React = {
 
   // This looks DOM specific but these are actually isomorphic helpers
   // since they are just generating DOM strings.
-  DOM: reactDOMFactories,
+  DOM: ReactDOMFactories,
 
   version: ReactVersion,