Log Message:
Fix build on recent NetBSD current:
net/route.h needs to be included before netinet6/in6_pcb.h.h and
net/if.h needs to be included before netinet6/in6_var.h.

While here add a patch file on the source of the configure script
which IMHO should have been added earlier.

Bump PKGREVISION to 1.

Note: I supposed the libdes related hunk in patches/patch-af had
been generated by an older than 2.59 autoconf script and carried
over from one net-snmp version update to the next.  This would
explain the slight differences about this hunk between the revision
I'm committing and the previous one.