Updated FeatureCodeBuilder and FeatureCode enum to include a flag for whether or not the feature code represents historical locations.  Added HISTORICAL and FEATURE_CODE fields to the index.  Updated AncestryIndexDirectoryBuilder to include new fields and store all ancestry records with each GeoName.  Updated log message in IndexDirectoryBuilder to output the number of records processed in addition to the number of documents written to the index.  Changed expected "London" GeoName in heuristics test to match new result in updated Gazetteer.