0.1.0

• The queue, out of the application it was written in: a job is a row written in the transaction that made it owed, claimed by a runner under a lease, run outside every transaction, retried with backoff and finished once, however often it was attempted.
• Its table, spool_jobs, is made by spool's own migrations, installed with the package and applied with rowtype-migrate up --source spool; a runner refuses to start on a database where it is missing or behind.