Fix for Bug 5570 - item types not showing on other editions

Fix for Bug 5570 - item types not showing on other editions

The item type which shows on other editions is the biblio-level
itemtype. XISBN.pm had some item-handling code, but I'm
removing it because it is unused. The editions tab should
now display item type only if item-level itemtypes are not
enabled.

Signed-off-by: Nicole Engard <nengard@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit bbd50b2d1219c904f3a7db3cfa49feca13bd8278)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>