Change module name from File_extractor to RDF_File_Extractor.
Change module name from RDF_loader to SPARQL_Loader.
Change module name from RDF_extractor to SPARQL_Extractor.
Change module name from SPARQL_transformer to SPARQL_Transformer.
Change module name from File_loader to RDF_File_Loader. Change other name modules - close #703 issue.