[Retros] Natch version 3.0 beta 2

[Pascal Wassong]

Hello all,

Silvio Baier and Thomas Brand have signaled to me that the beta 1
version of Natch 3.0 does not find the solution of the problem by
Nicolas Dupont published in the latest version of The Problemist.
Thanks to them to have found and reported the problem.

There was a bug in the code.  I just put a new version online with the
correction : Natch version 3.0 beta 2.

You can download it from http://Natch.free.fr

Best,
Pascal