Patch for Slovak DBPedia Spotlight

This patch includes:

* Lucene 3.6.x Slovak stemmer and analyser based on [Hana Pifková - Slovenský stemmer] (http://vi.ikt.ui.sav.sk/Projekty/Projekty_2008%2F%2F2009/Hana_Pifkov%C3%A1_-_Stemer)
* Simple Scala Stemmer.getStemmer(s) API
* Initial Slovak stopwords list

This also includes:

* Fix for bin/index_db.sh for latest pignnlproc toolchain

Tested locally and I have been able to generate and use basic Slovak Spotlight index/model. And annotated some sample data following [model-quickstarter] (https://github.com/jodaiber/model-quickstarter) also using [Airpedia Slovak New dataset] (http://www.airpedia.org/download/dbpedia-entity-types-in-31-languages/) instead of missing [Slovak instance_types data] (http://downloads.dbpedia.org/current/sk/instance_types_sk.nt.bz2).

Possibly adding manual [DBpedia Slovak mappings] (http://mappings.dbpedia.org/index.php/Mapping_sk) should give more/better results.