4.0 updates

vcl_fetch is now vcl_backend_response
https://www.varnish-cache.org/docs/trunk/whats-new/upgrading.html#vcl-fetch-is-now-vcl-backend-response

Hit For Pass change:
https://www.varnish-cache.org/docs/trunk/whats-new/upgrading.html#hit-for-pass-objects-are-created-using-beresp-uncacheable