sgetaz lab1 submission

The .c program has two known bugs:
 - Firstly, although the computed sum is correct within sort_sum.c just before it's return to main.c, when the 
   sum is printed in main there appears to be an overflow of some sort. Hours of debugging failed to find a 
  cause for the problem.
- Secondly, for some reason qsort fails to sort the final entry of the table. I do not know why this occurs