Acq: added UI controls to attach a claim policy to one or many lineitems

Acq: added UI controls to attach a claim policy to one or many lineitems

Incidentally, two bugs were fixed:
    1) Incorrect permacrud action entries in the IDL that stopped
       open-ils.pcrud from generating methods for the jub and acqlih
       classes.
    2) A widely used acq subroutine, retrieve_lineitem_impl, incorrectly
       cleared the purchase_order and picklist fields of its result if
       fleshing for those fields was not specifically requested. The
       correct behavior is to set those fields back to their integer
       foreign key values. This was causing several subtle problems.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@16284 dcc99617-32d9-48b4-a31d-7c20da2025e4