This undoes one part of commit 22ff9b53963f, at least for now.  The
ultimate decision is still up for discussion.  Maybe little solid
OTS-green dots as bullet points instead?

After we build a pdf, it is sometimes useful to attach some
information to the built file.  Here we do that as a YAML-formatted
block of lines appended to the PDF and marked in PDF syntax as
comments.  Our PDFs now carry some machine-readable metadata.

I've never liked the old letterhead styling.  This improves things a
bit.  This commit includes cc-licensed noun project icons.  I'll buy a
license to them so we don't have to include attribution on every doc
we send out.  We should consider doing attribution anyway when we can.

This might be useful for diffing against when your doc suddenly
doesn't build and you don't know why.  This doesn't save all the files
that go into making the doc.  It would be interesting to try to
snapshot them in some way.  It might even be interesting to collect
all the various files from all over and stik them in a dir so that
every build also makes a minimal one-dir version for slinging around.
Alas, this does none of that.

If a document comes in and there's no yaml frontmatter, we don't
jinjify.  You might not need any yaml frontmatter metadata but still
want jinja features (e.g. jinja macros).  In that case, add a dummy
var.

The reason for doing this is that legacy docs don't have any
frontmatter, and this is a convenient way to distinguish them.

 * Make -rXXXX versions for all builds, not just drafts
 * Add draft plugin
 * In template, set draft to trigger on both True and 'True'
 * Move path into PIPELINE definition
 * Silence some echo
 * Use .tex instead of intermediate_ltx
 * Simplify some bash
 * Let the plugin handle draft instead of passing it as an option
 * Cleanup .tex files

We can now do redacted and draft at the same time.

Refactor the jinja rendering and the redaction as a pipeline of
filters that run as needed.

It works, but needs some cleanup and documentation

When a venv is created, 'click' will now be installed into it.

This also removes the "dd" that was accidentally introduced into the
variable's value in commit 8463ab1fd21e, the same commit that made the
variable unused (I think we can guess the vi-ism that happened here).
So if we're ever restoring this variable, remember to remove the typo.

Hmm, I'm a little leery of putting this here, given the advice in the
log message of commit 45c93c61.  But we already have two docs
depending on it, and I didn't want to leave it sitting as a local
change (I'd meant to commit it and just forgot, and probably that all
happened before commit 45c93c61 was even made).  So I'm committing
it now, on the theory that it's a found dependency, but if we want to
revise our philosophy to be closer to what commit 45c93c61 says, I'm
open to that discussion, and I realize it might result in the
reversion of this change too.

There are two issues here.  First, LaTeX wisdom (and docs) say to load
hyperref as close to last as possible, or you're going to break
things.

Second, loading it here precludes loading it later with different,
conflicting options.  Generally, ots.sty should load things that are
essential.  Put the optional things in subsidiary style files or
individual docs.