Retaining the first named parameter in route resolution

Possible regression introduced in `3b6f1114 » tkambler `. Removed the `args.shift()`, which appeared to be stripping the first named parameter of route requests. 

To recreate issue:

    	router.on("/some/route/:id/:page/:line", function (id, page, line) {
		console.log(arguments); // returns only [page, line] 
	});

I ran Grunt on the project, but did not bump the semver. 

(Nice work, by the way!! Saved me a chunk of work and it works nicely in RequireJS.)