Bug 13227: Display856uAsImage displays images in OPAC in original size

Bug 13227: Display856uAsImage displays images in OPAC in original size

To test:
- catalog a record with 856$u = URL to an image, $q = img
- turn on the system preference Display856uAsImage
- make sure your record has been reindexed by Zebra
- verifiy the image indeed displays on the result and detail page
  in the bootstrap catalog.

The image shows in the original size, from the code it's meant
to display with a height of 100 px, but this won't work in bootstrap
as the height is set to auto with CSS.

Patch changes the XSLT to restore the former behaviour.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>