Make freshclam-observer work again

+ Disable outdated script hook as it is not shown in the UI
Merge branch 'master' into ejhernandez/av-loghelper

Conflicts:
	main/antivirus/ChangeLog
Added AV LogHelper for DB updates record

* Using notifier freshclam file which is now rotated
* Added File::ReadBackwards dependency to read from that file
Set proper length to source

* Use proper mason tag for doc
Setting proper test number
Merge pull request #334 from Zentyal/ejhernandez/av-loghelper

Ejhernandez/av loghelper