Dear Guix,

I would like to add 4store.  The official website is currently offline,
but there is an effort going on to get it back on line:
  https://github.com/garlik/4store/issues/137

Therefore, I would like to propose to keep the dead website link as this
should sort itself out in time.

I had to patch some build system files to avoid the need for Git and to
avoid "mkdir -p /var/lib/4store".

Now that I've triple-checked the patch, I hope everything is fine.

Thank you for your time.

Kind regards,
Roel Janssen