Revision 451442

Added ability to reference publication from which to fallback from,
This should resolves the problem of an xslt template trying to import itself when
xslt/page2xhtml.xsl -> imports -> template-fallback://xslt/page2xhtml.xsl -> imports -> template-fallback://xslt/page2xhtml.xsl
instead use   
xslt/page2xhtml.xsl -> imports -> template-fallback://{template1}//xslt/page2xhtml.xsl -> imports -> template-fallback://{template2}//xslt/page2xhtml.xsl

Adding pubids to your fallback:// protocols should also allow one to leave the xslt use-store on if used properly