Prior to this fix, changing the priority of any hold requests
in the queue of requests for a bib would convert
all item-level requests to title-level requests.
As part of this fix, improved display of the holds queue
so that item-level and bib-level requests can be more
clearly distinguished.
Documentation note: new screenshot of list of requests for
a bib in the staff interface.
Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
