- fixing broken unit tests and previously broken period archiving.

core/ArchiveProcessing.php

core/ArchiveProcessing/Period.php

core/DataTable.php

core/DataTable/Filter/AddSummaryRow.php

core/DataTable/Filter/Sort.php

core/ViewDataTable/GenerateGraphData.php

plugins/Actions/Actions.php

plugins/Goals/templates/release_notes.tpl

plugins/Live/Live.php

plugins/Provider/Provider.php

plugins/Referers/Referers.php

tests/core/ReleaseCheckList.test.php

tests/core/SitesManager.test.php

tests/resources/test-download-outlink-page.txt