Adding missing script for deleting biblioitems. This script refuses to delete

Adding missing script for deleting biblioitems.  This script refuses to delete
biblioitems which have items attached to it, but doesn't provide any
notification to the user that the biblioitem was not deleted.  Otherwise, it is
fully functional.  We still need a way to actually display  biblioitems that do not have
items attached to them.  Right now, the only way is to add an item to the
biblioitem, then delete the item and biblioitem one after another (because
there is no way to get back to the page that shows the "delete biblioitem"
button after the item has been deleted).