Regrouped app settings into a separate file.

Getting ready to implement authorization using a named-route mech.
Role's privilege map only stores allowed route name. When certain route
gets activated, the name will be checked with the req.user's privilege
map, it the map has the name enabled, this req gets through.
1. need a way to give name to a route;
2. need Resources meta obj to expose named routes for each Entity;
3. need a route to have the authorization guard after grabEntity(model
or meta obj) to check if this named route is allowed for this req.user.