ability to relaunch republisher on derived items

This may be a long term feature. To correct errors that were introduced during the editing of the scanned files, we should have the ability to relaunch republisher and derive the items again with the new scandata. We might need to not delete the proxies or re-run the preprocess for repub. Currently we are changing everything to jp2 so support for that may need to be added if we want to edit those files again.