D-Net

#919 renaming DocumentToResearchInitiative to DocumentToConceptId and DocumentToResearchInitiatives to DocumentToConceptIds

#1019 introducing integration test

#919 introducing integration test input and output

#919 introducing integration test containing empty input and output

#913 renaming DocumentContentUrl#contentSize to DocumentContentUrl#contentSizeKB changing field type from int to long, importing content size from ObjectStoreFile#fileSizeKB, updating dnet-objectstore-rmi dependency from 1.0.0 to 2.0.1-SNAPSHOT

#913 supplementing json files with newly introduced DocumentContentUrl#contentSize field value set to null

#840 moving IdentifierMapping from importer to common package

#840 renaming DeduplicationMapping to more generic IdentifierMapping

adding missing affiliation fields: countryCode, address, renaming country to countryName

adding missing affiliation fields: countryCode, address, renaming country to countryName