So it turns out fava, a web UI for beancount, is amazing, just amazing.
I recommend everyone use it and switch to it and hug it and tell it how
much they love and appreciate it.  You can see an example version
running here:

  https://fava.pythonanywhere.com/example-beancount-file/income_statement/

I got it "packaged" in the sense that the package works and runs.
However it isn't good enough for Guix yet.

 - Needs to be separated out into separate commits
 - I lost patience with several dependencies' test requirments and
   disabled tests
 - At least one dependency's tests requires a newer pytest.  That's not
   in master yet afaict because, based on this email:
     https://lists.gnu.org/archive/html/guix-devel/2019-10/msg00598.html
   It was waiting for Python 3.8.0 to hit core-updates.  I haven't
   looked yet whether that's happening or not.

I need to get back to other work right now, but figured that it was more
helpful than nothing to leave a "it works, but isn't quite right" patch
on the mailing list before I forgot.

It's really quite close, but I'm drowning in tasks ATM.  Maybe I can
come back to this, though if someone else beat me to it, I wouldn't
complain.

 - Chris