ClamAV

This is an initial pull request for review spanning ClamAV checks.  As of right now the following checks are performed:

1) Binary lookups/checks for clamscan & freshclam.
2) Cron check for fresclam.

I can add further functionality to checks for Cpanel::ClamScanner or even outgoing email scanning via Exim if this is seen as beneficial as my goal with this request was to keep the scope very limited.