TPac: batch holds from on-the-fly lists and bookbags

TPac: batch holds from on-the-fly lists and bookbags

* Enable the 'Place Hold' action in the drop-down for bookbag and
on-the-fly list items

* Place hold form now support lists of targets and will report error
conditions for each target

* Batch and individual hold overrides supported where appropriate

Signed-off-by: Bill Erickson <berick@esilibrary.com>