Bug 30713: Patron entry should limit date of birth selection to dates in the past

Bug 30713: Patron entry should limit date of birth selection to dates in the past

This patch adds to the configuration of the date of birth field in the
patron entry form so that the calendar widget prohibits the selection of
a date in the future.

To test, apply the patch and open a patron record for editing. Try to
select a birth date in the future using the calendar widget. You should
be limited to a selection of today or before.

Confirm that clicking the "Yesterday" and "Today" shortcuts in the
calendar widget works correctly.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>