Add option "delete after export" to export dialog

Most of the times, I want to export POIs / tracks and delete them after successful export, e.g. because I only collected them for mapping or for geotagging of photos from the DigiCam. Currently, I need to create the selection of POIs / tracks twice, once for exporting and once for deletion - quite tedious. It would be great to have an option "delete POIs / tracks after successful export", which may be disabled per default i.e. has to be activated for each single export.