CommandRouter should become router independent.

[PaulTondeur]

Ideally it should be independent of the router, but can be used to extend a router with or do something completely different. The name should also change in order to reflect these changes.

The following should be possible:

var MyRouter = Backbone.Router.extend(Backbone.CommandRouter).extend({
    //custom implementation
});

But also

var MySomething = Backbone.CommandRouter.extend({
    //custom implementation
});