Used to create player entities prior to reading the rest of a map,
all other initialization must be done after loading map (terrain/entities).
Be VERY careful in using other components here, as they may not be properly initialised yet.
settings is the object containing settings for this map.
newPlayers if true will remove old player entities or add new ones until
the new number of player entities is obtained
(used when loading a map or when Atlas changes the number of players).