This patch adds an OAI-PMH harvesting client to Koha.
The client runs as a daemon in the background. Users interact with the client
via the Koha web user interface, which communicates with the daemon via a unix
using a simple JSON-based protocol.
The harvester ingests MARCXML. You can harvest other metadata formats, but you
must use a XSLT to transform them into MARCXML, if you want them to be imported
You can supply your own download and import modules via the
configuration file, but the default modules supplied in this patch should
be good enough for your purposes. If they're not, raise a Bugzilla issue.
There is a cleanup_database.pl addition, because high volume harvesting
will cause the oai_harvester_import_queue table to fill quickly. This table
is not required for adding/updating records. It's mostly just for general
monitoring and audit purposes.