Bug 26800: Remove the use of jquery.checkboxes plugin from checkout page

Bug 26800: Remove the use of jquery.checkboxes plugin from checkout page

This patch removes inclusion of the jquery.checkboxes plugin from the
patron checkout page (circulation.tt). The plugin is unused.

To test, apply the patch and check out to a patron with checkouts.

- Open the checkouts tab and click "Show checkouts" if necessary.
- In the table of checkouts, confirm that the "select all" and "none"
  links in the "Renew" and "Check in" column headers work correctly.

Signed-off-by: Lisette Scheer <lisettes@latahlibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>