Add InsertType enum for solving loading data parts to SPARQL endpoint.
Add TripleCountHandler class - need if no triples from SPARQL endpoint were extracted.
Get/Set value keep extractFail information in RDFExtractorDialog.
add method isEmpty to TripleCountHandler.
Update method extractFromSPARQLEndpoint - using bolean extracFail in RDFDataUnitHelper interface.
Update method extract using exttractFail in RDFExtractor.
Add update implementation for extractFromSPARQLEndpoint method in BaseRDFRepo class.
Add TripleCounter interface for information about extracted triples.
Update TripleCountHander using interface TripleCounter.
Update StatisticalHandler class using TripleCounter interface.
Update implementation of extractFromSPARQL in case no triples in BaseRDFRepo class.
Update methods loadtoSPARQLEnpoint in RDFDataUnitHelper interface with InsertType.
Add InsertPartException class as extension of RDFException.
Update implementation of method loadtoSPARQLEndpoint in BaseRDFRepo class.
Update test using loadtoSPARQLEnpoint method.
Add InsertType to RDFLoaderConfig.
Update RDFLoaderDialog, add methods using InsertType.
Update calling extract method in RDFLoader - close #316 issue.