query_heart_beat() - query the status of an object's heartbeat
int query_heart_beat( object );
Returns the value with which set_heart_beat() has been called with on
'object'. If object is not given, it defaults to the current object.
If the object has no heart beat, 0 will be returned.
If no object is supplied, this efun will default to this_object().
heart_beat(4), set_heart_beat(3)