* if queue is empty and world.do_update is set, update world state file (and
* unset world.do_update) and write a single dot line to server out file, then
* read server in file for the next load of bytes to put onto the input queue.
* if queue is empty and world.do_update is set, update world state file (and
* unset world.do_update) and write a single dot line to server out file, then
* read server in file for the next load of bytes to put onto the input queue.