Implements the Bus Service Problem using Linux System V semaphores and shared memory

• Main process initializes shared memory structures and invokes other processes
• Agent process waits for customers and assigns tickets based on remaining seats
• Bus process increments depature times, boards waiting customers, then departs
• Customer process waits in line for a ticket, then boards the bus

$> make clean
$> make
$> ./main [number of busses]

Running ./main with no arguments defaults to 3 busses