v7.0-beta.70

* Issue **#1947** : Fixed NPE thrown when trying to unassign processing tasks by setting the assigned node to null.

* Issue **#1940** : Old searches are now terminated by the processing user.

* Issue **#1932** : Physical stream delete will no longer fail if a file or directory it wants to delete cannot be found, i.e. has been deleted by another external process.

* Fix log output counts for reference data.

* Add REST endpoint for purging reference data.

* Issue **#1938** : Fix missing ref loading errors/warnings, improve warning messages.