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/zebra/interface.c b/zebra/interface.c
index ed3ece2..c9f7132 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -674,7 +674,7 @@
   return ret;
 }
 
-DEFUN (no_zebra_interface,
+DEFUN_NOSH (no_zebra_interface,
        no_zebra_interface_cmd,
        "no interface IFNAME",
        "Delete a pseudo interface's configuration\n"
@@ -694,7 +694,7 @@
 
   if (CHECK_FLAG (ifp->status, ZEBRA_INTERFACE_ACTIVE))
     {
-      vty_out(vty, "Only inactive interfaces can be deleted%s", VTY_NEWLINE);
+      vty_out(vty, "%% Only inactive interfaces can be deleted%s", VTY_NEWLINE);
       return CMD_WARNING;
     }