Located URI visibility options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Before this, Evergreen restricted the visibility of bibliographic records
that make use of Located URIs in a way that attempts to model licensing
restrictions.

There now exists a global flag to allow sites the option of changing the
behaviour of Located URIs so that they act in a way analogous to copies
for visibility testing.  When the opac.located_uri.act_as_copy global flag
is enabled, Located URIs will cause their containing bib records to become
visible in searches where the URI is in scope to either ancestors of the
search library, as before, or descendents of the search library, as copies
do.  As before, if a preferred library is supplied by the user, it is
added to the list of visible org units to check.

Additionally, while the underlying UnAPI and supporting code was capable
of providing a reasonable and logical sort order for the Located URIs when
embedded as XML holdings elements, the client-facing UnAPI method was not
making use of that.  It now does, and uses the same sorting algorithm as
is used for copies.