Notification when there is no backup for today

[WadeBarnes]

When performing scheduled backup and verification, it is possible for a backup to fail due to a variety of reasons such as connectivity or storage issues. The scheduled verification for that day will verify the most recent backup, which will be the previously successful backup, which is likely to have already been verified. Without close inspection of the date stamp on the archive that was verified this produces what could easily be mistaken as a positive verification for the day (even though there should have been a failure notification for the backup).

For scheduled verifications:

• Detect whether the backup being verified is recent (for today, for example).
• Fail verification and send a notification if the archive is not recent.
• Add configuration parameters (flags and environment variables) to allow this functionality to be turned on or off.