Resolver interface to make Kowari talk to Fedora

Changed to correct component

Depends on fix for Ticket #10

(In [728]) Addresses #4, #10 and #72: multiple fixed and updates to FilterResolver?:

• Handle multiple models. The datastream a model's statements should be written to is part of the model definition so as avoid having to change the configuration and restart the server for new models.
• Flush outstanding queued items on server shutdown.
• Make various hardcoded params configurable.
• Made fedora-updater transaction aware so only committed stuff triggers an update
• Delete empty datastreams
• Avoid creating fedora objects unless really necessary.
• Updated fedora-updater for Fedora 2.1.1 (error message for no-such-datastream changed).
• Remove obsolete/dead code
• Added configurable filters for fedora-update to control which statements are written and whether any URI-rewriting should occur. Provided three different implementations: a very simple one that only handles Fedora URI's; a filter that tries to put things into Fedora in their proper places with the least mods, but falls back shortening and escaping URI's where necessary; and lastly a filter that writes all statements to separate Fedora objects (i.e. not the object indicated by the subject-uri). Neither of these are satisfactory, though, as they either don't fully fix the original problems in #10 or they invalidate the purpose of the updater (#4). They are being checked in here for historical purposes.

The idea of replicating the triples from Kowari into Fedora (the reverse of Fedora's ResourceIndexer?) isn't working - see #10 for details. To recap, this was being attempted for two reasons:

1. So that standard fedora modules/apps could be used unchanged, as the DC and RELS-EXT streams would be kept up-to-date by the replicator (filter-resolver).
2. To have a backup of Kowari, since there are known corruption problems in Kowari.

2 is being addressed in #187. Point 1 is probably not as big a deal as originally thought: the diringest has been replaced by our own ingest, the OAI-PMH stuff only uses DC. Furthermore, since [470] ingest puts a copy of things into both DC/RELS-EXT and the triplestore (see also #72).

Milestone Bugs deleted