Bug 25233: Staff XSLT material type label "Book" should be "Text"

Bug 25233: Staff XSLT material type label "Book" should be "Text"

This patch makes the staff client XSLT stylesheets consistent with the
ones for the OPAC, it also makes consitent the use of 'Text' when the leader6 = 't'

TO TEST:
1. Have a record with leader06 = 'a' and leader07 = 'c' 'd' or 'm'.
2. Check the staff client results and details page. See that the
   material type label says "Book"
3. Check the OPAC client results and details page. See that the
   materila type label says "Text"
4. Apply patch.
5. See that both staff client and OPAC results/details all now say
   "Text"
6. Set the leader6 = 't' and make sure that is says 'Text' on both the
   staff client and OPAC

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>