Recognise only a native promise from starterPack() and attach the catch
through Promise.prototype.then, so an installed pack's own then or then
getter never runs; such a pack is omitted and logged again instead of
failing the listing. A link count of 0 after the open reports the file
changed, not a hard link. Tests: a throwing then getter, a self-resolving
thenable, and a 0000 file refusing as unreadable.
jason.woltje
755ba3fa8b