Emulate inet_{pton,ntop} on systems that don't provide it.
diff --git a/configure.in b/configure.in
index 8ced0d0..2713336 100644
--- a/configure.in
+++ b/configure.in
@@ -1162,7 +1162,7 @@
AC_CHECK_FUNCS(alarm chown clock confstr ctermid ctermid_r execv \
flock fork fsync fdatasync fpathconf ftime ftruncate \
getgroups getlogin getpeername getpid getpwent getwd \
- kill link lstat mkfifo mktime mremap \
+ inet_pton kill link lstat mkfifo mktime mremap \
nice pathconf pause plock poll pthread_init \
putenv readlink \
select setegid seteuid setgid \