Bug 15853 - Add author and link columns to opac course reserves table

Bug 15853 - Add author and link columns to opac course reserves table

To test:
1 - Add some course reserves
2 - View the table in staff and opac, there is no column for author or
link
3 - Apply patch
4 - You shoudl see these columns
5 - Link should contain item uri if present, fallback to title 856$u,
  then be blank if niether

Sponsored by:
    Southeastern Wisconsin Information Technology Exchange, Inc (SWITCH)
    (http://caspian.switchinc.org/)

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Might be good to add this table to the column visibility tool if you
plan to add more columns.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit b89a601e5742b3067fa6ed508313acfce4e73e73)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>