Working code.

Need to fix the symbol table entries but other than that everything is now
working and life can resume as normal. I am waiting for Khoi to get back to me
on the rest of if I need to implement the symbol table issues.
Adding Lab 4.

Simple Lab, but must be added.
Updated git ignore file.
Adding the final version of Lab 3.

This was the cleaned up style that was submitted for the assignment.