nnrpd: adding blacklistd support

[Julien ÉLIE]

Hi Andreas,

> Adding it as --with-blacklistd sounds like the right thing to do, yes. 
>
>> I'll have a look.  As I do not run FreeBSD myself, it would 
>> be great if you could somehow test it.
> 
> When you say that you will have a look, does that mean that you want
> to rework the patch yourself?
>
> I'm willing (and was expecting) to open a pull request on GitHub and
> do testing as well as any required rewriting per your review.

Oh, that's kind of you.  It will save me time to do other work for INN
for the next major release.
Of course I don't mind your working on a pull request.
As we did not have GitHub until last year, I was accustomed to
reworking myself patches sent to our mailing-lists.

The idea would be to create a new m4/blacklistd.m4 file (based for
instance on m4/canlock.m4), add related glue in configure.ac and
Makefile.global.in, and surround the new code in nnrpd with
#if defined(HAVE_BLACKLISTD) instructions.

There is an entry in MANIFEST to add too.

Maybe a note about blacklistd in doc/pod/nnrpd.pod? (or any other
file you think more appropriate)
And mention --with-blacklistd in doc/pod/install.pod.

As GitHub continuous integration is run on Ubuntu, it cannot be
tested (so there is nothing to change in the ci directory I think).


Many thanks to you.  It is greatly appreciated!

-- 
Julien ÉLIE