adds check if callback is present for a given route, and returns if it is not. prevents errors trying to bind to routes without callbacks. per issue #2
adds check if callback is present for a given route, and returns if it is not. prevents errors trying to bind to routes without callbacks. per issue #2

boazsender/backbone.routefilter,DarkoKukovec/backbone.routefilter,DarkoKukovec/backbone.routefilter