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-restore.c b/iptables-restore.c
index d982fca..56812ee 100644
--- a/iptables-restore.c
+++ b/iptables-restore.c
@@ -129,9 +129,10 @@
 	const char *tablename = NULL;
 
 	program_name = "iptables-restore";
-	program_version = XTABLES_VERSION;
+	program_version = IPTABLES_VERSION;
 	line = 0;
 
+	xtables_program_name = program_name;
 	xtables_init();
 #ifdef NO_SHARED_LIBS
 	init_extensions();
@@ -153,7 +154,7 @@
 				break;
 			case 'h':
 				print_usage("iptables-restore",
-					    XTABLES_VERSION);
+					    IPTABLES_VERSION);
 				break;
 			case 'n':
 				noflush = 1;