base cygwin patches

[greg andruk]

on inn-patches, Russ Allbery wrote:
>> - make <arpa/nameser.h> and <resolv.h> optional for innfeed

> These don't appear to be needed at all, so I just deleted them.  I can't
> imagine what in there innfeed would have been using.

Maybe it was just a too-quick cut'n'paste from other k0deZ, but I was 
afraid someone may have put them there for a reason.

>> - fixup libperl's name, cygwin's looks like "libperl5_6_1.a"
> Applied, with some slight tweaks.  I don't quite understand why this is
> needed, though; Perl should really tell us the correct link line for its
> libraries.

It's fixed in Perl 5.8, but that's still in Cygwin's experimental branch.

> I took another route with this.  The uses in innfeed were safe, so in
> nnrpd where IOV_MAX was used to declare arrays, I just capped it at 1024.
> Thankfully ?: operators are allowed in integer constant expressions.

Even better!

Upcoming stuff: I've a need to disable mmap, but only in innd/icd.c; and 
to use pipe() instead of socketpair() even though the latter exists.  I 
can't really use test programs because the bugs I'm avoiding both tend 
to result in hung processes, and I'm hoping that future releases will 
make these problems go away.  Are configure command switches okay for 
these two?