Bug 12895 repair dropbox mode

Bug 12895 repair dropbox mode

One day late patrons were restricted even with dropbox mode activated

1) Check in the calendar (Tools/Calendar), that the
   previous days you are about to use as date due are
   really entered as opening day (never know).
2) Add a suspension in the suspension days parameter
   of the circulation rules (Administration/Circulation
   and fine rules) to the MOST specific category of
   borrower and MOST specific type of document among the
   existing rules of the LOGGED IN Site(cf explications
   in the circ-rules page).
3) Choose a borrower using the search by category and an
   item through the advanced search using the limit by type.
4) Checkout the item selecting the previous opening date
   in the Specify-due-date box.
5) Click on Circulation in the upper menu, then on Checkin
   and check the Book drop mode. The Book drop date showed
   should be the previous opening date.
6) Check in the item : you can see that the patron is restricted
7) apply the patch
8) Redo 1 to 5 : Now, you can see that the patron is not restricted.
9) If you redo the test with two day late, you will see that
   the patron is not restricted : that's ok because his
   restriction of one day is already finished.
10) If you redo the test with more than two day late, you see
    that the patron restriction is, as expected, one day shorter
    than it were if the item had been returned without dropbox mode.

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>