[Cin] Working on adding GPL license attribution for all program files

[Andrea paz]

I feel similarly to IgorBeg. Without going into too much detail about
Open licensing, so as not to drive Phyllis crazy making she to pursue
rare data lost in the menadirs of time, I would just leave a general
Authors window for all the code, without having to put them in every
file header.

For example, I would say that CinGG uses code from multiple versions
of Cin and also from external programs. For code derived from CinHV I
would put a link to the CinHV page; I would do the same for CinCV
(maybe it is better to ask Igor Vladimirsky, on which page to link)
and CinCVE (Einar). Instead, the original contributors to CinGG can be
made explicit clearly in this same authors window.

In any case, the most competent person to ask is definitely Igor
Vladimirsky, especially for Cin HV; CV and CVE.

Finally I would hear suggestions from the various contributors to
CinGG, for the best method by which to be cited; whether in each
headers of their code or in general without going into detail.