Upgrade libpcap to 1.8.1 (Nmap-specific patches not yet applied)

libpcap/gen_version_c.sh

@@ -0,0 +1,11 @@
+#! /bin/sh
+echo '#include <pcap/export-defs.h>' > "$2"
+echo 'PCAP_API_DEF' >> "$2"
+if grep GIT "$1" >/dev/null; then
+	read ver <"$1"
+	echo $ver | tr -d '\012'
+	date +_%Y_%m_%d
+else
+	cat "$1"
+fi | sed -e 's/.*/char pcap_version[] = "&";/' >> "$2"
+