Let's refactor the directories first ( issue 647278 ) before doing this. Then we can do one directory at a time, to make reviewing a little easier.

I also propose doing the tests that currently use Audit, because such tests are basically ready for testharness.  The tests that aren't using Audit end up essentially being a rewrite, so do the low-hanging fruit first.

All the tests that we wanted to convert have been.  Need to decide what to do about the tests that weren't converted, but that's a different issue.