Bug 9211 - days_between wrong behaviour

Bug 9211 - days_between wrong behaviour

As noted in comments #15, #16 and #17 of bug 8486, and its API,
Koha::Calendar->days_between should always returns a positive number
irrespective of the relative order of the parameters. This is still an
open bug, which arised when rewriting the Calendar.t file (Bug 9209).

Regards
To+

Sponsored-by: Universidad Nacional de Córdoba
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Added Paul's sign-off line, as despite it showing up in Bugzilla, it
wasn't on the patch.