add route name to callback

when sharing the callback , the route name is useful for recognize , check the example.
```javascript

$.routes.add('/courses/', "courses", routeHandler);
$.routes.add('/course/{id:int}', "course", routeHandler);

function routeHandler () {
    switch (this.routeName) {
        case "courses":
            console.log("courses");
            // TODO render template courses
            break;
        case "course":
            console.log("course ->" , this.id);
            // TODO render template only one course
            break;
    }
};
```