Bug 2720 - Overdues which debar automatically should undebar automatically when returned

Bug 2720 - Overdues which debar automatically should undebar automatically when returned

This patch adds a more extensible and flexible debarments system to Koha. The fields
borrowers.debarred and borrowers.debarredcomment are retained for compatibility and
speed.

This system supports having debarments for multiple reasons. There are currently
three types of debarments:
OVERDUES    - Generated by overdue_notices.pl if the notice should debar a patron
SUSPENSION  - A punative debarment generated on checkin via an issuing rule
MANUAL      - A debarment created manually by a librarian

OVERDUE debarments are cleared automatically when all overdue items have been returned,
if the new system preference AutoRemoveOverduesRestrictions is enabled. It is disabled
by default to retain current default functionality.

Whenever a borrowers debarments are modified, the system updates the borrowers debarment
fields with the highest expiration from all the borrowers debarments, and concatenates
the comments from the debarments together.

Test plan:
 1) Apply patch
 2) Run updatedatabase.pl
 3) Verify the borrower_debarments table has been created and
    populated with the pre-existing debarments
 4) Run t/db_dependent/Borrower_Debarments.t
 5) Manually debar a patron, with an expiration date
 6) Verify the patron cannot be issued to
 7) Add another manual debarment with a different expiration date
 8) Verify the 'restricted' message lists the date farthest into the future
 9) Add another manual debarment with no expiration date
10) Verify the borrower is now debarred indefinitely
11) Delete the indefinite debarment
12) Verify the debarment message lists an expiration date dagain
13) Enable the new system preference AutoRemoveOverduesRestrictions
14) Set an overdue notice to debar after 1 day of being overdue
15) Check out an item to a patron and backdate the due date to yesterday
16) Run overdue_notices.pl
17) Verify the OVERDUES debarment was created
18) Return the item
19) Verify the OVERDUES debarment was removed
20) Disable AutoRemoveOverduesRestrictions
21) Repeat steps 15 though 18, verify the OVERDUES debarment was *not* removed
22) Add issuing rules so that an overdue item causes a temporary debarment
23) Check out an item to a patron and backdate the due date by a year
24) Return the item
25) Verify the SUSPENSION debarment was added to the patron

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>