ftpd: add idle and absolute timeouts. This is a security issue,
 otherwise ftpd may end up hanging indefinitely.

function                                             old     new   delta
timeout_handler                                        -     110    +110
ftpd_main                                           2019    2115     +96
packed_usage                                       25662   25685     +23
handle_upload_common                                 306     322     +16
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/0 up/down: 245/0)             Total: 245 bytes

diff --git a/include/usage.h b/include/usage.h
index 25a7162..e787543 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -1281,7 +1281,7 @@
      "\n	-f	Force file system check" \
 
 #define ftpd_trivial_usage \
-       "[-wvS] [DIR]"
+       "[-wvS] [-t N] [-T N] [DIR]"
 #define ftpd_full_usage "\n\n" \
        "FTP server\n" \
        "\n" \
@@ -1294,6 +1294,7 @@
      "\n	-w	Allow upload" \
      "\n	-v	Log to stderr" \
      "\n	-S	Log to syslog" \
+     "\n	-t,-T	Idle and absolute timeouts" \
      "\n	DIR	Change root to this directory" \
 
 #define ftpget_trivial_usage \