Bug 6027 - Delete biblios if deleting all their items in batch deletion

Bug 6027 - Delete biblios if deleting all their items in batch deletion

Optionally delete bibliographic record when batch deleting items, if no items remain on the record.

Adds deleting of reserves to DelBiblio. Since subscriptions are deleted automatically,
it made sense for deletion of reserves to maintain the same behavior.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
I like the way this works, and it does. Passes tests.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>