Bug 8111 - Language chooser display problem in self-checkout

Bug 8111 - Language chooser display problem in self-checkout

- Adds required JavaScript and JavaScript linked files
- Updates CSS with changes relevant to this feature which had
  been made to the main CSS file.
- Removes an image file which has been made obsolete now that
  sco.css uses the main image sprite like opac.css does.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>