Placed record id logic in the select-id module.
Updated record id logic to use the URL field of the OAI-PMH handle, if any, as the _id and to save the hashed _id as the id.
Updated revision check logic to use the ingested document _id field when comparing to an existing CouchDB document id.
Merge branch 'master' into thumbnails_download_preview

Conflicts:
	scripts/poll_profiles