Adds & removes markers on the map when a player dies, to aid in finding and recovering their body.
DeathMarkers/control.lua:49: attempt to index field 'death_markers'(a nil value)
https://forums.factorio.com/viewtopic.php?f=88&t=83966
I haven't been able to reproduce this particular problem, but I believe I've solved it in the release, 0.3.1. Sorry for the long delay.
