webminstats 2.23 (stable) released

Webminstats is a Webmin's module which display a graphical log of historic information. It's modular in design, as to be able to log everything from CPU usage to mail queue.
This release is to fix some issues :
* sysstat-action-lib fix bug on _action_exec
* (audit,dns,mysql) fix cloning module on keys file (bug #104)
* (battery) avoid warnings if no battery (on VM)
* (hddtemp) allow use of hddtemp-lt to replace deprecated hddtemp (ticket #4)
* (ping) allow icmpv6
* (display.js) patch to display the date in a fixed place (patch # 3 from userecho)
* (battery, uptime) rename tab_param sub
* (firewall) suppress warnings from nft