Bug 23623: Use the new API for changing privacy settings (guarantors)

Bug 23623: Use the new API for changing privacy settings (guarantors)

This patchset makes opac-memberentry.pl use the API instead of the old
svc scripts for ajax calls, for setting privacy configuration in the
OPAC.

To test:
1) Disable OPACPrivacy
2) Enable AllowPatronToSetCheckoutsVisibilityForGuarantor
3) Enable AllowPatronToSetFinesVisibilityForGuarantor
4) Have a known patron be the guarantee of someone (so things display)
5) Log into the OPAC, go to the 'your personal details' tab
6) Change 'Allow your guarantor to view your current checkouts?' and
click the 'Update' button.
=> SUCCESS: Operation succeeds
7) Reload the tab
=> SUCCESS: The page reflects the expected changes (i.e. the API did it
        right)
8) Repeat 6 and 7 with the 'Allow your guarantor to view your current
fines?' option
=> SUCCESS: It works as well
- Sign off :-D

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>