Implemented the terminating condition based on a specified number of time steps

The simulation will end after endingTimeStep iterations.  The score is
calculating by if a person has exited a building and if they have
finished.  There is no penalty for if a person wasn’t spawned.
Able to run the simulation without debugging (printing to console) PedestrianSimulation, Person, or MapGridData
More Debuging and created methods to reset the static next id for Cell and Person