Replacement for Deprecated / Removed BaseTokenFilterFactory

When writing plugins for Solr you’d previously extend the BaseTokenFilterFactory, but at some time since I last built trunk, that changed to TokenFilterFactory – which is located in the util package of lucene instead.

Diff:

- import org.apache.solr.analysis.BaseTokenFilterFactory; 
+ import org.apache.lucene.analysis.util.TokenFilterFactory; 

...

- public class xxxxxFilterFactory extends BaseTokenFilterFactory 
+ public class xxxxxFilterFactory extends TokenFilterFactory