Reconsider caching of certain values by OPAC

[Galen Charlton]

The Evergreen OPAC code caches various values in memcached and mod_perl code in Apache backends. Most of the caching is set up by init_ro_object_cache() in OpenILS/WWW/EGCatLoader/Util.pm.

For "field safe" IDL classes, the contents of the table, if retrieved at all, are cached in memcached and the Apache backend processes. As a consequence, if values such as global flags or record attribute definitions get updated by the user, it can take both an Apache reload/restart and removing the key(s) from memcached to see a change take effect.

This can lead to situations like the one found in bug 2053047, where it is unclear how to make a configuration actually take effect.

It would be good to provide ways to overcome the caching upon certain configuration changes without having to restart server-side processes.