Change route logic to redirect to module-specific URL

We now redirect to module specific route (either setup or auth) depending on whether a user account exists or not.  After redirect, a module should take over and handle this request.  This also requires adding new module-specific routes (see password route in server-config.js).

@krulwich, @suprbh, @ceg1236 
(The second parameter in my code snippet is the request method, eg 'get' or 'post')