Stackable spawn points

Right clicking on bed should create a new spawn point in a stack instead of replacing old one. Whenever a bed is destroyed, it should read the stack and fallback to the previous/last bed on which a spawn point was set on. This way it's possible to set home base far from spawn, and go out to explore from there, and sleep at night while doing so, without worrying about respawning at world spawn in case of accidental death