LP#1167541: Use Patron home org for pickup lib instead of staff's

LP#1167541: Use Patron home org for pickup lib instead of staff's

When staff are placing a hold for a patron, we should use the patron's
preferred pickup location, and failing that, their home library rather
than the staff's home library.

To test
-------
[1] In the web staff client, search for a title to place
    a hold request on, using a patron record
    whose home library is different from the home library of
    the staff member you are logged in as.
[2] Note that the pickup location defaults to the staff
    account's home library.
[3] Apply the patch and repeat step #1. This time, the default
    pickup library should be the home library of the patron.
[4] Set a preferred pickup location for the patron, then
    repeat step #1. This time, the default pickup library
    should be the preferred pickup location just set.
[5] Repeat steps #1-#4 using the XUL staff client; note that
    for step #3, it will be necessary to rebuild the client.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Chris Sharp <csharp@georgialibraries.org>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>