Bug 8972 - Due Date set to 100 years ago

Bug 8972 - Due Date set to 100 years ago

In order to prevent submission of dates with ambiguous two-digit
years this patch makes date-due input fields read-only so that
users must use date/time picker.

Other minor fixes:

- Adding missing labels
- Adding common class wrapper to datepicker for checkout and renewal
- Correcting focus handling on "specify due date" field (should
  focus on barcode field after a date has been selected).
- Removing trailing comma from JavaScript (breaks IE)

To test, try typing an invalid number in any of the date due entry
fields: Under 'specify due date,' 'renewal due date,' or the
confirm "invalid" date dialog (after specifying a date in the past).
Manual entry should not work. Choosing a date/time using the
widget should work.

Signed-off-by: Melia Meggs <melia@test.bywatersolutions.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>