add useful operator, functions prototypes and a beginning implementation of NSGA-II
Little corrections.

Implement normally the main loop of NSGA-II (not definition of function)
add crowding distance computation
Continue implementation of NSGA-II (function fast non-dominated sort)

(all functions implemented before and on this commit must will be debugged when it will be possible)
Implement mutate operator and random generation on chromosomemintint, and also domination operator.
add operator to perform breeding using crowded tournament for NSGA-II
begin debugging dast non dominated sort
debugging of fast non-dominated sort normally completed !

And little clean up
Simple display for Single objective GA