Spawning behavior

[ttk2]

BetterShards should provide a config option with a list of "spawning worlds" when a player dies without a bed a spawning world will be selected at random from the list and a location within that world also selected at random the player will then be respawned at that location.

Optional features:

when configuring spawning worlds allow for bounding boxes for where people spawn inside those worlds

add a feature to weight the location selected to places nearby players.

[Maxopoly]

Mostly done, replaced by #30