lp978095 auto-canceling lineitems

lp978095 auto-canceling lineitems

"Acq: lineitems display as "on order" even after all copies have been cancelled"

When a copy (lineitem detail) on a lineitem is canceled through the UI, all of
the sibling copies are examined, and if they also happen to be canceled, then a
cancel attempt is made on the parent lineitem.

The cancel reason fed to the lineitem cancelation attempt will be the last
cancel reason on an examined sibling lineitem where Keep Debits is True, or
failing that, the cancel reason used wih the copy just canceled.

The UI will refresh to the lineitem view when such an auto-cancelation happens.

Signed-off-by: Jason Etheridge <jason@EquinoxInitiative.org>