* fibonacci.nit: refine Int, the class of all integers, to add a Fibonacci function.
* procedural_array.nit: simple use of arrays without defining new classes.
* clock.nit: a simple class to track time on a wall clock.
* fibonacci.nit: refine Int, the class of all integers, to add a Fibonacci function.
* procedural_array.nit: simple use of arrays without defining new classes.
* clock.nit: a simple class to track time on a wall clock.