7146 (Update timestamps when deleting a biblio)

7146 (Update timestamps when deleting a biblio)

Currently, when you delete an item, the timestamp column in deleteditems is
updated with current time. (This comes from an [unintentional] additional
update statement in DelItem.) It makes deletion time visible.
In the past, the marcxml was updated too at that moment, resulting in an
updated timestamp in biblioitems too. The timestamp in biblio was not touched.

If you delete a biblio however, the timestamps in deletedbiblio and
deletedbiblioitems do not reflect time of deletion. They still show the time of
last update before the record was deleted. This last update can be extracted
from MARC field 005 too.

This behavior is not consistent nor logical. I would suggest to add a statement
in DelBiblio to force updating the timestamp in deletedbiblio(items) too. It
makes the time of deletion visible in the record too. The time of deletion of a
biblio can be very useful for e.g. synchronizing purposes.

Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>