deprecate or remove openurl_map.pl

[Galen Charlton]

Evergreen ships with a Perl script (openurl_map.pl) and some Apache configuration to map "/openurl" with various search parameter to an /opac/extras/opensearch URL.

Although there is no documentation whatsoever of this feature, it presumably was created to ease configuring an OpenURL resolver to direct searches to an Evergreen catalog without making the resolver's configuration do much manipulation of the OpenURL to pass it the ILS.

Because this is implemented as a RewriteMap, an instance of openurl_map.pl is spawned for each active Apache virtual host. Not a huge deal, but it does consume some memory.

The issue: it very much looks like this feature is not used very commonly, or perhaps even at all. I can't find any signs of anything invoking /openurl among Equinox's hosted customers in the past week, and unlike OpenSearch itself, it isn't something that is auto-discoverable.

Consequently, for the sake of tidiness and a (generally tiny) reduction in system resources, I propose that openurl_map.pl and its corresponding Apache configuration be removed.

If it turns out that there _are_ sites depending on the mapping, I propose that it instead be some combination of:

- documented
- commented out in the Apache config
- rewritten as a small mod_perl handler