SolrYard IndexingDestination should support creation of FST models

The SolrYard Indexing Destination should support the creation of FST modles for the FST linking engine.

The CPU intensive task of creating the models should be done once at indexing time and not at runtime for every Stanbol instance using an index.

This will add an optional FST configuration to the SolrYard destination that will create the FST models for configured fields. The models will be stored in the data directory of the SolrCore in the 'fst' folder (the default used by the FST linking engine)