Enable syslog by default
    
    This gives more relevant data to journal than logging in stdout. Also, pid file
    is no longer needed, since we're a Type=dbus service.
    
    The flat logging file is removed since it's not needed when we're logging into
    journal. We probably can remove the logrotate file too.
    
    The -u argument is moved into the service file as we can't really remove it
    without changing the service's Type.