Bug 27937: Set datepicker when date is valid

Bug 27937: Set datepicker when date is valid

When validating dates in JavaScript it is acceptable to have single digit days or months e.g,:
2011-6-16

When parsing in Koha::DateUtils->dt_from_string we die on these

This patch uses JS to set the datepicker which normalizes the date as Koha expects

To test:
 1 - Add new patron
 2 - Enter birthdate as 2/11/1986
 3 - Complete required fields
 4 - Save
 5 - Get ISE
     The given date (2/11/1986) does not match the date format (us) at /kohadevbox/koha/Koha/DateUtils.pm line 175
 6 - Apply patch
 7 - Repeat 1-2
 8 - Note that when you change focus (click on another field) the date is formatted as '02/11/1986'
 9 - Save patron, success!
10 - Edit patron, try setting DOB to 2/1/1986
11 - Change focus and note date is formatted as '02/01/1986', save
12 - Repeat with other settings of system preference 'dateformat'

Signed-off-by: Donna <donna@bywatersolutions.com>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@helsinki.fi>
Bug 27937: (QA follow-up) Fix indentation

Signed-off-by: Joonas Kylmälä <joonas.kylmala@helsinki.fi>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>