Bug 7412: Pre-filling items in cataloguing

Bug 7412: Pre-filling items in cataloguing

Pre-filling of items: remember what was in the previous item filled, to be able to create multiple items quickly.

By default, all subfields are prefilled when the PrefillItem syspref is on, unless you specify which fields
you want to prefill in the SubfieldsToUseWhenPrefill syspref.
With a value of "f u v", only the $f, $u and $v will be prefilled, for example.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Rebased and QAed.