MINOR: lua: add ip addresses and network manipulation function

Add two functions core.parse_addr() and core.match_addr() where are used
for matching networks.
diff --git a/include/types/hlua.h b/include/types/hlua.h
index 698786d..d2aaa4a 100644
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -150,6 +150,20 @@
 	int len;
 };
 
+struct hlua_addr {
+	union {
+		struct {
+			struct in_addr ip;
+			struct in_addr mask;
+		} v4;
+		struct {
+			struct in6_addr ip;
+			struct in6_addr mask;
+		} v6;
+	} addr;
+	int type;
+};
+
 #else /* USE_LUA */
 
 /* Empty struct for compilation compatibility */