knights license?

[Alexander Semke]

Hi Luca,

> I'm writing to confirm the license of knights, which will be back in KDE
> Applications 18.12. Currently there isn't a LICENSE file in the repository,
> which is important for distributions to confirm the license without having
> to dig into source files.
> 
> From a quick look it seems GPL-2.0+. Would you be able to confirm this?
> Thanks a lot.

In many header files I see "either version 2 of the License or (at your option) 
version 3 or any later version accepted by the membership of KDE e.V. ". This 
is from the original author and I'm totally fine with this. Would you add th 
LICENSE file?

I don't see such a license file in Cantor, neither. Should we also add it here?

Thanks and Regards,
Alexander