[AD] No more GNA

[SiegeLord <siegelordex@xxxxxxxxxx>]

So apparently gna.org will be shutting down soonish, see 
https://mail.gna.org/public/project/2016-11/msg00001.html for the 
announcement.

Right now we use gna.org for the downloads and the file hosting, while 
Github contains the website, repository and the bugs.

For the downloads, in principle we can attach the release archives to 
tags on Github without much issue, but some of the files will have to be 
placed elsewhere, perhaps in the website repository. Github has a total 
size limit for the repositories, so we might possibly need to upgrade to 
their paid offering (I can provide the funds).

For the mailing list, I think it is a great thing to have, because the 
historical context that you can glean from the archives is invaluable 
sometimes. Github doesn't provide mailing list hosting, and in fact it's 
not at all obvious where to find a place that does.

There is an option to go back to SourceForge for the mailing list and 
perhaps the files (although their mucking around with the files was one 
of the reasons we left in the first place).

Alternatively, it'd be neat to just self-host such things. I am somewhat 
annoyed that I'll have to go back to homebrew and other places to update 
where to download our archives, it'd be great if it could just be 
liballeg.org/files/allegro/...tar.gz in perpetuity. Again, I can provide 
the funds but unfortunately none of the expertise, as I've never had to 
host a website before, nevermind a mailing list.

Any opinions on how to proceed? We should decide and implement things 
soonish, I think we have 1-2 months before gna closes for good.

-SL