Adding  funtionality to allow the third-party application to have direct access to Lucene

Removing Activable as per the refactor work in OpenFileState... For 2 reasons:

- There was a way through the code (I haven't worked out yet) which caused NullPointer in activate, where the boolean value got out of sync with the nulled out resources on deactivate

- Performance analysis showed that 15% of time in quick fire requests was spent opening up the index searcher (it seems the Lucene doc supports this view: "For performance reasons, if your index is unchanging, you should share a single IndexSearcher instance across multiple searches instead of creating a new one per-search" http://lucene.apache.org/core/old_versioned_docs/versions/3_5_0/api/core/org/apache/lucene/search/IndexSearcher.html) And elsewhere it says that opening up a IndexReader is an expensive operation. 

- Changed the TermVector setting for Strong numbers to allow us to get frequencies out

- Exposing the LuceneSearcher to allow people to do their own complicated tasks on top of the functionality that JSword provides.