this means that we only ever look at the immediate parent. with a nested menu tree, this would be wrong. i guess the right thing would be to keep the method getMenuForSubject but use a strategy similar to https://github.com/symfony-cmf/RoutingBundle/blob/master/Doctrine/Phpcr/RouteProvider.php#L78 to get a bunch of parent menu nodes in one go. then we take the `Menu` if there is one in this list, otherwise we take whatever comes right before `MenuNode`s start.

then the ground would be ready to also show the whole MenuNode hierarchy breadcrumb. (though i would add that in a separate PR, as we need at least a config option to limit how many we want to show)