changed BulkImportOptions class -- refactoring
changed test method for BulkImportOptions#initPrepareOptionParser()
changed BulkImportOptions class -- it uses withValuesSeparatedBy method
changed BulkImportOptions class -- added initUploadOptionParser method
changed BulkImportOptions class -- deleted 'withOptionalArg' method call from the class
changed BulkImportOptions class -- added 'showHelp' method
minor change of test case of BulkImportOptions class