LP1182519 Per-Hold Behind Desk Value

LP1182519 Per-Hold Behind Desk Value

The true/false value for behind_desk is now stored directly on the hold
object for more accurate tracking of the location of captured holds.
If configured, patrons can now set their preferred value for behind the
desk holds.

 * DB/IDL changes to support the new column
 * API support for loading the setting from the patron for cases when no
   value is provided by the caller.
 * Staff client grid column definition for the Behind Desk field
 * Hold counts in the staff client now show total, available, and
   behind-desk (at the workstation).
 * Printed hold receipt now uses the behind_desk value on the hold to
   decide if a hold is behind the desk.
 * Release notes

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