Bug 13497: Remove the pref AddPatronsLists

Bug 13497: Remove the pref AddPatronsLists

The pref AddPatronLists does not work as expected if 'generic' is
selected.
Indeed a patron should be linked to a valid patron category (see the
constraint borrowers_ibfk_1 in the DB structure).

Test plan:
0/ Confirm that the AddPatronLists does not work as expected if you choose
the generic patron types.
1/ Delete all you patron categories and check that the interface invites
you to create one.
2/ Confirm that you are able to create a patron and to link it to a patron
category you have created.

I could not verify step 1/, because at least one Patron category
can not be deleted (Staff, since I'm logged in as a Staff patron
and you can not delete categories that are in use).
Tested 0/ and 2/
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes QA script and tests.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>