fixing #3115 (search method : TaxonServiceImpl.findTaxonByDescriptionElementFullText() is missing Distributions) + test for #3063 (hibernate search: CdmMassIndexer.purge() fails, it does not empty the index.)
fixing #3115 (search method : TaxonServiceImpl.findTaxonByDescriptionElementFullText() is missing Distributions) + test for #3063 (hibernate search: CdmMassIndexer.purge() fails, it does not empty the index.)