Changed is_sorted() to check sorting against an array that has been previously sorted by the new quicksort() function also added within this update.  Main now generates an array to be sorted, sorts the array via quicksort, and then stores a copy of the sorted array for is_sorted() to check against bogosorted versions of the same array.  This method is a little more efficient and when you're working with a program designed to loop through billions of iterations every little bit counts...