Fixing the logic of SelectionSort.c and adding modular programming design

[wassim31]

In C folder , SelectionSort.c , the logic implemented is similar to BubbleSort.c instead of real logic of selection-sort which is the following : Finding the smallest element in the array , swap it's location with the first element in the array , and doing that until the array is sorted . But in the following code d7f3626 , they're comparing adjacent elements , j and j+1. So i will fix the issue #197