If itemnumber is sent to catalogue/moredetail.pl use it

If itemnumber is sent to catalogue/moredetail.pl use it

If itemnumber is part of the url for catalogue/moredetail.pl
put it to use.
This happens in members/boraccount.pl if a fine is attached to a
barcode.

This patch makes moredetail.pl show only the item specified by
itemnumber.

Implements some changes to the patch suggested on
patches@koha.org
give visual cue on UI and a link out.
More friendly pruning of the other items.

Thanks to Galen Charlton and Joe Atzberger

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>