Bug 9403: Material type icons not showing for XSLT default view in intranet

Bug 9403: Material type icons not showing for XSLT default view in intranet

Implements the material type icons shown in the MARC21 XSLT result list
of the OPAC for the intrant result list.

Also adds the system preference DisplayIconsXSLT as an intranet analogue
for the OPAC system preference DisplayOPACiconsXSLT and corrects the
descriptions of both preferences in the syspref editor.

To test:
0) Run database update to add new system preference
1) Activate default XSLTResultsDisplay
2) Check the new system preference DisplayIconsXSLT shows up correctly
  and is activated by default. Compare descriptions between DisplayIconsXSLT
  and DisplayOPACiconsXSLT.
3) Check the intranet result list for icons showing up after 'Type:' and
  before the corresponding description. Detail pages should be showing
  the 'Type:' as before.
4) Turn off DisplayIconsXSLT.
5) Check the line containing 'Type:', format and audience information is now
  hidden from the result list.
6) Check that the 'Type:'line is also hidden from the detail page.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>