Add two additional configuration items to allow a retry count and retry interval (in seconds)

[ellenmarquez]

Add two additional configuration items to allow a retry count and retry interval (in seconds):

Sometimes a random network issue occurs, and it would be nice to have the utility wait for a configurable amount of time (in seconds) and then attempt it for a configurable amount of times, before sending failure alerts.

I suggest the addition of two new configuration items (preferences.json) and supporting logic to allow a retry count and retry interval (in seconds) before failing and sending error emails when “emailuponerror” configuration setting is enabled.