* Changed so that fft works!!! Updating when a task was NOT spawned was wrong - I was adding the task critical duration to the parent's critical duration when I should have just been adding the task's duration to the parent's critical duration.
* Also, moved instrumentation from cout to file outputs - making it thread safe and added util/critical_path.cc to collate the output folder.
* There is still a race condition that arises on 8 threads. Daaang.