[PATCH 0/2] Add 'guix publish' command

[David Thompson]

This patch set has been a long time coming.  Thanks to Ludo for helping
me solve the last blocking issue this morning.

This new utility allows anyone to publish their /gnu/store directory
over HTTP, exposing a Hydra-compatible API.

To use it, simply run `guix publish` on one of your machines, then tell
your other machines to use that one to fetch substitutes:

    guix archive --authorize < your-server-key.pub
    guix-daemon --substitute-urls=your-server:8080

Someday, Guix will support multiple substitution servers, which will
make this feature a lot more useful.  Being able to fetch substitutes
from hydra.gnu.org *and* from other Guix users that you trust will be
awesome. :)

TIA for the code review.

-- 
David Thompson
Web Developer - Free Software Foundation - http://fsf.org
GPG Key: 0FF1D807
Support the FSF: https://fsf.org/donate