Attempts to convert Permatrac Wiki to Markdown format.

Last time I had to do something like this it looks like I took the
Trac -> HTML -> html2markdown path.  Could do that again.  Recipe for
fetching the HTML:

     wget -r --user=sra@hactrn.net --ask-password https://permatrac.noc.ietf.org/wiki/

Slightly better recipe:

     wget -m -R '*[?]*' --user=sra@hactrn.net --ask-password https://permatrac.noc.ietf.org/wiki/

But either way, `wget` seems to be non-terminating when walking this
site, even if it throws away .999 of what it retrieves.  In theory,
adding `-np` would have fixed this; in practice doing so causes it not
to recurse at all.  Grrr.

Scripts from rpki.net/doc/*/*.{sh,py,xsl}, included here under tools/.

The other approach is converting Trac wiki directly to markdown.
There are hacks for this, in Ruby:

  https://gist.github.com/somebox/619537

But there are also Python versions, which are a bit more tractible.
Several of them included in tools/ too.


The most promising approach looks to be `tools/trac2md.py`, which is a
bit crude but is written in a relatively sane style so should be fixable.