Add named urls

[kennydude]

As per ticket #1

Another potential addition would be to include named URLs a la Django, so you can do:

SuperRouter.Route.create({
 url: "users/:user_id",
 route: function(){
   alert("normal routing stuff here!");
 },
 name: 'user-detail'
});

SuperHistory.navigate({name: 'user-detail', id: 4});