Dear Guix,

I would like to be able to conveniently analyze Guix package
dependencies using general purpose network analysis software such as
igraph. To achieve this, I have added another backend to Guix and which
is exposed via guix graph which spits out a three column table that,
while not technically and edge list, is readily transformed into one
with minimal data munging.

Please see the attached patch file which I have created with `git diff'
from my working tree since I am not yet comfortable with more advanced
git workflows.