Bug 7719 - Change state of controls based on whether boxes are checked

Bug 7719 - Change state of controls based on whether boxes are checked

Some OPAC interface controls cannot function unless a checkbox is
checked. Examples:

- Placing a hold on multiple items in the cart window or on a list view page
- Adding tags to multiple items in the cart window or on a list view page
- Removing one or more items from the cart window
- Removing one or more items from a list on the list view page
- Adding one or more items to a list from the cart window

This patch moves these controls into a separate div in which links
are enabled or disabled based on whether checkboxes are checked. It
does so on two pages: The lists view page (when viewing the contents
of a list) and in the cart window.

Links which are in their disabled state should not perform any action.
After checking one or more checkboxes the links should become active
and behave normally.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Works in chrome and firefox (latest). Passes tests.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>