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/

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.