Notifications improvement

Setup resending notifications until cleared.

Like resend notification for storage usage every 10 min for example until its within limits. 

Or when something is down, resend the notification.

We do this with other tools in Pushover. It will keep sending alerts that go trough the silent settings of your device. So you know when there is a serious issue you need to look at it. Since one gets many notifications in a day things can be missed. Full disks or stopped servers/services. Should be to set repeated messages for example.