Messages get lost on server restart

[davidben]

Not too surprising, but yeah, that happens. As more people use Roost, this becomes less okay. Can we do something more clever?

I suppose we could actually serialize state to hack around that, but then they get reordered because of retransmits.

[davidben]

Especially annoying is that, until I finally resolve all #25, server restarts usually happen while the server is swapping a lot. So it actually takes it quite a while to shut all the way down. More likely to lose something.