ProcessDeparture function
1. Current Time = Arrival time of Departure Event;
2. Output a message with time and event;
3. Remove Item from Line since a person is departing;
4. Delete an event from the list;
PersonInfo = Line front person’s info;
Insert in Event List a Departure Event for Current Time + PersonInfo’s TranTime;
Update Totalwait Statistics by (Current Time - PersonInfo.Time);