Bug 14874 - Add ability to search for patrons by date of birth from checkout and...

Bug 14874 - Add ability to search for patrons by date of birth from checkout and patron quick searches

This patch adds a new syspef 'DefaultPatronSearchFields' which defines
the fields that should be used when searching for a patron if none are
defined.

To test:
1 - Aply patch, updatedatabase
2 - Ensure patron search has not changed
3 - Add dateofbirth to new pref
4 - Ensure things work wll
5 - Experiment with adding and removing other fields from borrowers
table
6 - prove t/db_dependent/Utils/Datatables_Members.t

Tested together with followup. Works as described.
Signed-off-by: Marc Véron <veron@veron.ch>
Bug 14874 (QA Followup)

    Fix atomicupdate file name

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>