[PATCH] zabbix_agentd: Update to 6.0.15 + WebGUI Log viewer

Hi all

Since CU 173 the Zabbix Agent userparameter "ipfire.net.fw.hits.raw" did no longer work correctly due to grep complaining about a stray \ since grep v3.8. This is fixed in PATCH 2 of this set (by simply removing the stray 's).

And since I had to up the pak version for this fix I decided to also update the zabbix_agentd binary from 6.0.6 to 6.0.15 despite the fact that there are no subtantial code changes in the Zabbix Agent for Linux part of the codebase. (see PATCH 1 of this set)

I also had a Zabbix Agent logfile viewer for the webGUI still lying around here, waiting to be finished and released, I also included that in this updated pak version (PATCH 3) integrating Zabbix Agent a bit more into IPFire.

Regards

Robin