Merge pull request #4309 from mmoss/addons-warning-fix

Concatenate warning message, due to parsing issues

packages/react/addons.js

@@ -1,8 +1,11 @@
 var warning = require('./lib/warning');
 warning(
   false,
-  "require('react/addons') is deprecated. " +
-  "Access using require('react-addons-{addon}') instead."
+  // Require examples in this string must be split to prevent React's
+  // build tools from mistaking them for real requires.
+  // Otherwise the build tools will attempt to build a 'react-addons-{addon}' module.
+  'require' + "('react/addons') is deprecated. " +
+  'Access using require' + "('react-addons-{addon}') instead."
 );
 
 module.exports = require('./lib/ReactWithAddons');