bundle: write helper to remove old policykit files
we need to remove the old files for polkit permissions to openvpn, which are a security risk. this ticket tracks the inclusion of the helper in the bundle.
(from redmine: created on 2014-05-09, closed on 2014-06-17, relates #5650 (closed), relates #5634 (closed), relates #5625 (closed), precedes #5588 (closed))