Failed jobs will now be automatically retired. This is controlled by two
new settings:
retry_on_status - a list of statuses which will be consided failures and
result in a retry
max_retries - number of retries before giving up
- added initialze and finalize methods to workloads, which were the only
major extension types that did not have them
- Semanatics for initialize/finalize for *all* Extensions are changed so
that now they will always run at most once per run. They will not be
executed twice even if invoke via istances of different subclasses (if
those subclasses defined their own verions, then their versions will
be invoked once each, but the base version will only get invoked
once).