Bug 14570: Make it possible to add multiple guarantors to a record

Bug 14570: Make it possible to add multiple guarantors to a record

This patch adds the ability to set an unlimited number of guarantors
for a given patron. As before, each guarantor may be linked to another
Koha patron, and all the behavior that applies to a given guarantor
remains the same.

Test Plan:
 1) Apply this patch
 2) Run updatedatabase.pl
 3) Find some patrons with guarantors, verify the still have their guarantor
 4) Test adding and removing guarantors on a patron record, both Koha users and not
 5) Verify the "Add child" button works
 6) Verify NoIssuesChargeGuarantees still works
 7) Verify tools/cleanborrowers.pl will not delete a guarantor
 8) Verify the guarantors are displayed on moremember.pl
 9) Verify the guarantor is removed by members/update-child.pl
10) Verify the guarantor is removed by misc/cronjobs/j2a.pl
11) Verify import patrons converts guarantor_id, relationship, contactfirstname,
  and contactsurname into a guarantor
12) prove t/Patron.t
13) prove t/db_dependent/Circulation.t
14) prove t/db_dependent/Circulation/NoIssuesChargeGuarantees.t
15) prove t/db_dependent/Items.t
16) prove t/db_dependent/Koha/Patrons.t
17) prove t/db_dependent/Members.t
18) prove t/db_dependent/Patron/Relationships.t

Signed-off-by: Kim Peine <kmpeine@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Agustin Moyano <agustinmoyano@theke.io>
Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>