Factorio has no fired event, so the log was written on every ammo
inventory change, which includes loading rockets for the first time and
swapping between rocket types. The last seen name and count of each ammo
slot is now kept per player, and a shot is only logged when a slot holds
the same ammo with one fewer, or empties from a single round. Only the
three configured ammo types are logged, rather than every ammo change.
Fixes#242