Bug 17812 - Return focus to barcode field after toggling on-site checkouts

Bug 17812 - Return focus to barcode field after toggling on-site checkouts

This patch changes the behavior of the checkout form so that after
checking boxes in the "checkout settings" panel the cursor focus is
automatically moved to the barcode field.

To test, apply the patch and enable OnSiteCheckouts and
decreaseLoanHighHolds system preferences.

- Open any patron account in circulation.
- Expand the "Checkout settings" panel.
- Click the label or checkbox for "Automatic renewal", "Don't
  decrease checkout length based on holds" and "On-site checkout"
- Confirm that the focus has moved to the barcode field.

Works as advertised.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Marjorie Barry-Vila <marjorie.barry-vila@ccsr.qc.ca>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Mason James <mtj@kohaaloha.com>