Logrotate is not used because I didn't found an easy way to configure it
to handle the compression/deletion of log files already rotated by
rsyslog (it is probably possible, but I found the script to be easier).
A call to sendLogsToRemote for logs received through RELP/UDP has
been added (to send them to Logstash/Redis/…), so common.conf's prefix
must be lower than collector.conf's.
Note: future "third-party" config files will also call sendLogsToRemote
and thus will also have to use a prefix higher than 10.
