LP1754455: Sanity checking and auto-strip 852s when using --items

If a user passes --strip / inform them that their request to output nothing
but empty records has been denied. Also auto-remove existing 852 fields when
using --items because only actual holdings data should be output in that case.

Signed-off-by: Jason Boyer <JBoyer@equinoxOLI.org>
Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>