Feature(theme): add nightmode react logic

We wait to load the user before applying the theme
as we will begin aggressively caching most of the react
app routes. This means we can not depend on user data to
determine.

common/models/user.js

@@ -599,6 +599,7 @@ module.exports = function(User) {
       .toPromise();
   };
 
+  // deprecated. remove once live
   User.remoteMethod(
     'updateTheme',
     {