Bug 16315 - OPAC Shelfbrowser doesn't display the full title

Bug 16315 - OPAC Shelfbrowser doesn't display the full title

This patch adds subtitle information to the display of titles in the
OPAC's shelf browser.

To test, apply the patch and make sure OPACShelfBrowser is enabled.

- View the detail page for any title in the OPAC which has items.
- Click the "Browse shelf" link next to any item in the holdings table.
- The titles in the shelf browser should display with all subtitle
  information as defined in Keywords to MARC mapping.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Adding 245a and c as 'subtitle' in Keywords to Marc make them
show on shelf browser.
No errors.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>