From: Hasso Tepper <hasso@estpak.ee>

Add the 'no interface' command to all the daemons and vtysh. now it's
possible to delete interface from routeing daemons as well only if it
doesn't exist in os.

http://hasso.linux.ee/zebra/ht-no_interface_fix.patch
diff --git a/ospf6d/ospf6d.c b/ospf6d/ospf6d.c
index 8b50b5a..04609ba 100644
--- a/ospf6d/ospf6d.c
+++ b/ospf6d/ospf6d.c
@@ -729,6 +729,7 @@
   install_element (ENABLE_NODE, &reload_cmd);
   install_element (CONFIG_NODE, &router_ospf6_cmd);
   install_element (CONFIG_NODE, &interface_cmd);
+  install_element (CONFIG_NODE, &no_interface_cmd);
 #ifdef OSPF6_STATISTICS
   install_element (VIEW_NODE, &show_ipv6_ospf6_statistics_cmd);
   install_element (ENABLE_NODE, &show_ipv6_ospf6_statistics_cmd);