Bug 17457: Adv. Acquisition search with ISBN variations

Bug 17457: Adv. Acquisition search with ISBN variations

Advanced acquisition search will now follow the "SearchWithISBNVariations" system preference.

Test plan :
0) Make sure you have orders pending or completed
1) Enable SearchWithISBNVariations if it is not enabled
2) Search for one of your orders by its ISBN, it should appear
3) Search for the same order by a variation of its ISBN, I used this website to find it : http://www.hahnlibrary.net/libraries/isbncalc.html
You should not get a result.
4) Apply patch
5) Repeat step 2-3. You should get a hit both times.
6) prove t/db_dependent/Acquisition.t

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>