implement openvpn output observer
So we can trigger transitions in the connection state machine.
(from redmine: created on 2013-09-20, closed on 2013-10-21, relates #4060 (closed), precedes #3262 (closed), precedes #3790 (closed))
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So we can trigger transitions in the connection state machine.
(from redmine: created on 2013-09-20, closed on 2013-10-21, relates #4060 (closed), precedes #3262 (closed), precedes #3790 (closed))