 - If a matched line is followed by a line like "last message repeated xxx
   time", include it in the mail
 - Substitute the select with no timeout followed by a sleep to a select with
   timeout, if possible.
 - Add an #ifdef to use dnotify (linux/Documentation/dnotify.txt) to watch the
   log files when available  (no, because dnotify notifies at directory level,
   and it would wake up quite often if the watched file is on a busy directory
   like, for example, /var/log)
 
 * Done in 0.2.8

 + Make it possible (activated by a specific option) to send mails that contain
   exactly all and only the log lines that appeared since the last mail was
   sent
