Enh 6403: Record local use stats when checking in unissued materials

Enh 6403: Record local use stats when checking in unissued materials

Adds a new system preference, RecordLocalUseOnReturn, which when active will change the statistical
entry type from "return" to "localuse" in AddReturn() if the material was not on loan when returned.
The intended use-case here is for libraries with 'open' book drops, in which patrons can put locally
used (but unissued) materials.

Adds a small message to the user interface to confirm that Local Use was recorded.

This change opens up the possibility to record more types of statistics on return; one would just need
to update the $stat_type variable accordingly.

Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>