Add a copy of the GPL license

[tuliom]

trafficstars

The GNU project recommends [1] that projects maintain a copy of the GPL license. This is also the recommendation from some Linux distributions [2].

This file has been downloaded from https://www.gnu.org/licenses/gpl.txt.

[1] https://www.gnu.org/licenses/gpl-howto.html [2] https://docs.fedoraproject.org/en-US/packaging-guidelines/LicensingGuidelines/

[tuliom]

I've just added a new patch in order to replace the old address of the FSF.

[skangas]

BTW, RMS claims this is a violation of the GPL:

https://lists.gnu.org/archive/html/emacs-devel/2021-12/msg02285.html