Added average turnaround time to metrics and changed a word or two.
Changed readyqueue::update() to updateWaitTime() and added an extra method updatePriority() to update priority seperately.
The priority now updates everytime the scheduler is called (everytime a process leaves the cpu).
also changed some stuff in the logger. I had the order of processes mixed up in the interrupt log method. Also I removed the -1 from getCurrentBurst in the CPU burst log so it shows the first burst as 1, not 0. The IO burst starts at 1 so I wanted to be consistent.
Merge pull request #54 from trevs231/metrics

Average turnaround time