Allow Express 3 route middleware

Express 3 routes are often in this format, with any number of middleware functions before the actual request handler:

    app.get('/', middlewareOne, middlewareTwo, requestHandler)

This wasn't allowed by the old module definition. Varargs are only allowed at the end of a parameter list so I've changed it to a list of functions that can have any arguments. There's less type checking in these route calls as a result, but worth it to be able to use route middleware.