Format improvements

No change in logic
backfill - improve resource map build

This change prevents creation of some back-to-back records with
the same resources, but different times.
backfill - continue after failed job start

When a decision is made to start a job, if for some
reason that job's start failed, the backfill scheduler
would previously just exit. With this change, it logs
the event and reserves the resources expected to be
used and continues down the job queue.
backfill logging improvement