Bug 11232: Add new syntax for facets definition on koha-indexdefs-to-zebra.xsl

Bug 11232: Add new syntax for facets definition on koha-indexdefs-to-zebra.xsl

This patch changes koha-indexdefs-to-zebra.xsl to correctly process a new syntax
for defining facet indexes on the XML files.

It also changes the retrieval file to allow access to Zebra's internal data from
Zoom (i.e. access to zebra::facet:*).

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: David Cook <dcook@prosentient.com.au>
Seems to work with DOM and MARC21.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>