UCBG-212: Add event handler to update taxon access codes.
UCBG-212: Stash previous field values in the context on beforeDocumentModification, so they can be retrieved later.
UCBG-212: Allow refNames of taxon records to be passed to updateAccessCode, in addition to csids.
UCBG-212: Update access codes of taxon records when taxon names are removed from collectionobjects.
UCBG-212: Add comments.
UCBG-212: Add comments.