mkfs silently truncates "zkapissuer-database" to "zkapissuer-datab" and
everything falls apart.

The point is this is where PaymentServer's persistent state goes.  That
includes vouchers but might include more stuff too.

The hardware modules can now configure this fileSystem in a way appropriate
for themselves and the issuer module can enable that configuration when it is
enabled itself.

Using AWS is what causes it so using AWS can be what fixes it, too.

For consistency reasons: Even if they had a perfectly good swap
partition already, and also for AWS hosts.

Also put library code in a library directory