Change repeater to retry on error

 * Retry is only attempted if task responds with error. Successful tasks do
not have to be retried which is the primary difference repeat and retry.

* Once a retry is triggered delay and break-on are taken into considertaion.
Modified tests appropriately and renamed types and properties appropriately.

Change-Id: I660cac05c20e791c0620add99d9d348f4bd910d1