Additional options for scheduled backups

[GrBeach]

Currently in the Backup Manager you can specify the period (daily, weekly, monthly) and the number of backups to keep. This makes it impossible to manage backups for multiple periods. For example, if I want to have 7 daily backups, 4 weekly backups and 3 monthly backups there's no way for me to do that using the panels.

So rather than specifying the period of the backup how about specifying the number of daily, weekly and monthly backups to keep. A value of 0 would mean don't run backups for that period.