RFE: `strftime(3)`-like format specifiers in log file name

[opty77]

Please add support for strftime(3)-like format specifiers in log file name so one can use templates like /var/log/messages-%F in /etc/syslog.conf and doesn't have to use logrotate(3) (except corner cases, e.g. /var/log/wtmp at least).

Beyond the scope of this issue and for discussion, syslogd might eventually support non-date/time related specifiers like host name.

(Based on cronolog recommendation by user "colo" on channel #openwrt at OFTC IRC network.)

[opty77]

I changed my mind and now consider this useless. If you think otherwise then please open your own issue.