faster archive by calculating the recursive count only if needed

core/Archive/DataTableFactory.php

core/ArchiveProcessor.php

core/DataTable/Row.php

plugins/Actions/Archiver.php

plugins/Contents/Archiver.php

plugins/CustomVariables/Archiver.php

plugins/DevicePlugins/Archiver.php

plugins/DevicesDetection/Archiver.php

plugins/Events/Archiver.php

plugins/Goals/Archiver.php

plugins/Provider/Archiver.php

plugins/Referrers/Archiver.php

plugins/Resolution/Archiver.php

plugins/UserCountry/Archiver.php

plugins/UserLanguage/Archiver.php

plugins/VisitTime/Archiver.php

plugins/VisitorInterest/Archiver.php