implement bailing out of AddReturn if IndependantBranches is on

implement bailing out of AddReturn if IndependantBranches is on

If IndependantBranches is ON and user attempts to return an
item at a library other than the item's home library, bail out.
This action, which was previously just a suggestion in the code,
is now required to ensure that the item doesn't get its
holdingbranch set to the library at which the attempt to return
the item was made.

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>