Add various shell scripts and the initial conductor tests (which did
not work reliably--which is why I resorted to shell scripts again).

Some of these scripts were built up over the years, copied, pasted, mangled,
and re-adjusted. A lot of this would benefit from a more formal proper
framework to be run regularly.

I ended up running most of these in parallel in endless loops.
See jail-vnet.sh for a start.

Sponsored by: The FreeBSD Foundation; and others