Moved all tutorials into tutorials/
Added old databases assignments to old_assignments
Added info2820_assignment2 (old_assignments).
Completed hw4 COMP3520
removed homeworks. no longer tracked.
Completed exercise 3 in w10 lab.
Finished part of w11 info3320 lab.

- Still haven't added exceptions.
- Haven't ran the code against the tests.
- I think the default constructor doesn't quite work.
updated the tutorialsheet
W7 COMP3520 lab [not fully working]

- There's a bug in either pcb_terminate or pcb_start. The child process needs
  to be killed once the remaining_cpu_time is up however, kill isn't correctly
  killing the right process.

  This could be due to where I'm getting the pid in pcb_start or I'm not using
  kill correctly.