I have nagios checks that monitor stunnel processes and complain if
they aren't running properly. In wheezy and older those looked for 6
running processes, but starting in jessie (5.x change?) each stunnel
is a single process. I searched the documentation and upstream
site/mailing list for an explanation but didn't find anything. The
closest I found was a mailing list maessage that seemed to say it
had something to do with libwrap and thread safeness. I would like
something in the documentation that addresses this:

Why did older versions have 6 processes?
When did it change to a single process?
What changed that allowed this?
What external dependencies are needed for this?
  (ie if I wanted to run an stunnel4 backport on wheezy, what else
   would I need)

Thanks,