Fixing DocumentationViewer::handleAction() to work with SS 3.1
Fixing DocumentationViewer::handleAction() to work with SS 3.1

silverstripe/silverstripe-docsviewer,camfindlay/silverstripe-docsviewer,camfindlay/silverstripe-docsviewer,silverstripe/silverstripe-docsviewer,dhensby/silverstripe-docsviewer,dhensby/silverstripe-docsviewer