ter means error not retry, only retry when told to

Requests that return status ```ter...``` were being resubmitted, but got into a state where the callback was never called.
Since ```ter``` means transaction error, we should not be trying to resubmit it.
Go ahead and allow the ```terRetry``` status to retry, but send the rest of the statuses through the failure handler so the error is properly returned.

Fixes #17.