LP1209291 vandelay item import defaults

LP1209291 vandelay item import defaults

Via org settings, support auto-generation of call numbers and barcodes
for items imported via Vandelay's Item Import interface.  Support
settings for applying a local prefix string to auto-generated call
numbers and barcodes.  For both, the prefix defaults to "VAN".

Similarly, support default copy location and circ modifiers.

The new org unit settings:

vandelay.item.barcode.auto
vandelay.item.barcode.prefix
vandelay.item.call_number.auto
vandelay.item.call_number.prefix
vandelay.item.copy_location.default
vandelay.item.circ_modifier.default

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>