Bug 9570 - view plain not working in ccsr

Bug 9570 - view plain not working in ccsr

The code in opac-showmarc.pl isn't smart enough to find the xsl files in
the "default" (prog) theme if the ccsr theme is enabled, so the "view
plain" option on opac-MARCdetail.pl fails ever time.

This patch copies some path-handling code from XSLT.pm to improve xsl
file path handling when dealing with a "sub-theme."

To test, view the MARC view in the OPAC and click the "view plain" link.
This should work correctly in prog and ccsr themes and with different
languages enabled (keeping in mind the ccsr theme will fail in general
for languages other than en).

Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Checked plain view works in both prog and ccsr themes now.
All tests and QA script pass.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>