Introduce and use fe_timeout_add_seconds

This should allow the operating system to be a bit more lax about
timeouts, allowing more efficient power management.

src/common/server.c

@@ -249,7 +249,7 @@ static void
 close_socket (int sok)
 {
 	/* close the socket in 5 seconds so the QUIT message is not lost */
-	fe_timeout_add (5000, close_socket_cb, GINT_TO_POINTER (sok));
+	fe_timeout_add_seconds (5, close_socket_cb, GINT_TO_POINTER (sok));
 }
 
 /* handle 1 line of text received from the server */