Broken link to "Choosing a License"

[fingolfin]

I guess we should run a broken links checker on gap-system.org, and fix what we find...

One that I just stumbled over is that on http://www.gap-system.org/Packages/Authors/authors.html, it links to http://sage.math.washington.edu/home/wdj/gap2007braunschweig/gap-package-licensing-info.html in the section "Choosing a License", and that link is dead.

A modern alternative to that link might be http://choosealicense.com/

[olexandr-konovalov]

Thanks - I've replaced outdated link to http://choosealicense.com/ in 96832d1. I will close this issue now since #15 is already about the same (see an update I've just posted there).