Bug 24249: OPAC lists page should require login for login-dependent operations

Bug 24249: OPAC lists page should require login for login-dependent operations

This patch modifies opac-shelves.pl so that login is required if the
requested operation is anything but "view" and "list."

The patch also modifies a couple of "Log in to create a new list" links
so that they point to the list creation form instead of opac-user.pl.

To test, apply the patch and go to the main lists page (the list of
lists) in the OPAC while not logged in.

 - Click the "Log in to create a new list" link.
 - Log in.
 - You should be taken to the "Create a new list" form.
 - Also test the "New list" link shown in the toolbar when you're
   viewing the contents of a list.
 - When not logged in click the "Lists" menu in the page's header menu.
   Clicking "Log in to create a new list" should take you to the login
   form and then to the list creation form.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>