added the rest of our opcodes and another interupt for system call - for
printing string or printing int. My prompt is not printing after it
advances the line, weird -- not sure how to begin investigating for
this. I will see if it is just the syscall or maybe more wide spread
issue. Next commit should have some comments and modularized code a bit
where I see fit. Of course this project could be modularized more, and I
know where -- but I have already given this hours upon hours upon hours
-- lots of pain... There are also some issues that will creap up in
project 3 unless I address them now... such as, I am passing pcb(0,255)
for address space -- however, in project 3 we will need to handle 3
different address spaces.