Multiple commands now use Django's command output and error facilities, removing many loggers.
All calls to logging.basicConfig have been removed, letting Django's settings alone handle the logging configuration without being overriden.
A few loggers that were defined in modules but not used at all have been removed.
The S3FileMixin logs for instances that do not have S3 objects (such as elements that should not have thumbnails) are now marked as debug to avoid polluting the production logs.
The permission check failure logs are now marked as debug to avoid polluting the production logs (we already see HTTP 400/401/403 anyway).
The Transkribus credentials error log has been removed (we already have a HTTP 400).
The logging configuration now ensures that all django.*, arkindex.*, rq.* loggers are set to INFO.
arkindex rqworkerdoes show the logs for every job now!
