Bug 21013: Missing itemtype for checkut makes patron summary print explode

Bug 21013: Missing itemtype for checkut makes patron summary print explode

This patch moves retrieval of the item type description from the script
to the template using the ItemTypes template plugin.

To test, apply the patch and locate an item which is checked out to
someone. Modify the database record for that item to remove the item
type (items.itype).

View the print summary for the patron who has that item checked out. The
page should display correctly. Checked-out items which have an item type
should show that item type description correctly.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>