Bug 21409: Add column configuration to course reserves

Bug 21409: Add column configuration to course reserves

This patch adds columns configuration and print/export options to two
tables: The table listing courses and the table listing titles reserved
for a course.

To test you should have more than one course and multiple title reserved
for at least one course.

- Apply the patch and go to Course reserves
  - In the table of courses, confirm that all DataTables controls work
    correctly: paging, filter, column visibility, export, etc.
  - View a course with multiple titles reserved. Test all DataTables
    controls on this table too.
- Go to Administration -> Columns settings
  - Change the settings for the courses and reserves table and confirm
    that these changes are applied correctly.

Signed-off-by: Caroline Cyr La Rose <caroline.cyr-la-rose@inlibro.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>