Check for requisites

[bstillman]

We should add a check for xtrabackup, perl-Digest-MD5, mail, etc. Maybe this should be a setup/configuration script.

[tanji]

Where does the perl-Digest-MD5 dependency come from?

[tszelak]

Can you expand on the details of the mail setup?
I don't see any reference for adding the mail server or port#
The bgbbackup.cnf only references maillist and mailsubpre

[bstillman]

I need to add mail server config info. Right now it just sends it from the local mail. I'll open a new issue for that.