libxtables: prefix/order - program_name

Split XTABLES_VERSION into xtables and iptables, and encode the
xtables soversion into the extensions instead. This makes it possible
to upgrade iptables without having to recompile 3rd-party extensions
(if the libxtables version matches, of course).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/iptables-save.c b/iptables-save.c
index e615de9..d08ec4b 100644
--- a/iptables-save.c
+++ b/iptables-save.c
@@ -74,7 +74,7 @@
 		time_t now = time(NULL);
 
 		printf("# Generated by iptables-save v%s on %s",
-		       XTABLES_VERSION, ctime(&now));
+		       IPTABLES_VERSION, ctime(&now));
 		printf("*%s\n", tablename);
 
 		/* Dump out chain names first,
@@ -137,8 +137,9 @@
 	int c;
 
 	program_name = "iptables-save";
-	program_version = XTABLES_VERSION;
+	program_version = IPTABLES_VERSION;
 
+	xtables_program_name = program_name;
 	xtables_init();
 #ifdef NO_SHARED_LIBS
 	init_extensions();