Text to go in the release notes:
This enhancement enables items that are on hold to be renewed with a due date specified by the user. It is enabled by the new "AllowRenewalOnHoldOverride" system preference.
It can appear in two locations:
1. In the "Checkouts" table on the Patron Details screen. It is now possible to select on loan items that would otherwise fulfil a hold request to be renewed. When such an item is selected, an additional date selection box is displayed to allow the user to specify the due date for all on hold items that are to be renewed.
2. In the Circulation > Renew alert screen. When a barcode of an on loan item that would ordinarily fulfil a hold request is entered, the usual alert is displayed indicating that the item is on hold, it is still possible to override this, and renew, however it is now also possible to specify a due date.