Bug 9052 - followup: fix the YUI CSS locations for SCO

Bug 9052 - followup: fix the YUI CSS locations for SCO

This is followup to the previous YUI-fixing patch, and simply causes the
self-checkout page to load the YUI files via the sco CSS file,
and that gets re-written at package build time to work.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Tested on a package installation using packages built by
Mirko Tietgen and a git dev installation.

To test:
1) Enable WebBasedSelfCheck system preference
2) Enter login date for staff user in AutoSelfCheckAllowed... prefernces
3) Go to the self checkout page:
   .../cgi-bin/koha/sco/sco-main.pl
4) Verify all pages have the usual look, CSS, Javascript and images
   look normal
5) Verify the same is true for translated templates

Manual: http://manual.koha-community.org/3.10/en/selfcheckout.html
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>