Drop dependency on LaTeX, I will restore it if we ever get the PDF build
back.

Before, we weren't checking out the right branch on a fresh clone

Use the rather-nice racket/commandline library to parse them rather than
the ad-hoc junk I was using before. This makes it possible to pass in
the path to geni-lib

Still need to handle errors, though!

This will be used instead of hardcoding it

The bits I haven't yet converted are due to pnext not yet being
put into the sphinx documentation and members of pg.Node and
pg.Interface being underdocumented

Point people to the emulab copy of the repo, and the docs that we now
build as part of this manual

This will be cross-linked from the main documentation as needed

Right now, only built for CloudLab

Need to have a more general way of figuring out where geni-lib is
installed.

This reverts commit 3b683360.

This really should have been done on a branch, I still have work to
do to update the accompanying text

Uses some clever tricks to (1) put an invisible copy of the code in the
document (which doesn't get munged by the highlighter), (2) construct a
funky javascript URL that functions as a 'save as' button

I would still like to:

(1) Style it a bit better
(2) Set the filename to something sensible

Use the new form that doesn't require addResource(), and use the new
style for the portal.context

Unfortunately these haven't been accepted upstream and so are somewhat
subject to change.  However, the interface described here does match
what is currently installed on ops, so it is real for the time being.

This will allow download of the built artifacts from the CI system