slow_shutdown - informs the mud that a slow shutdown is in progress
int slow_shutdown( int minutes );
This master apply is called when the driver can't allocate any more memory from the heap and had to use its reserved memory block. This function can only be called if the "reserved size" config file setting was set. The minutes remaining to driver shutdown is passed to this function. If this function does ont exist, or returns zero, the driver shuts down immediately.