Add timeout query parameter to container stop and restart

The Docker API supports custom timeouts for the [stop](http://docs.docker.io/en/latest/reference/api/docker_remote_api_v1.9/#id12) and [restart](http://docs.docker.io/en/latest/reference/api/docker_remote_api_v1.9/#id13) container commands. This adds the ability to utilize custom timeouts when calling `container.stop("timeout" => "100")` and `container.restart("timeout => "100")`.