Backlog/112

Mainly implements issue https://github.com/telefonicaid/fiware-connectors/issues/112.

It implements issue https://github.com/telefonicaid/fiware-connectors/issues/104 as well.
> Please observe Cygnus itself may solve the problem thanks to the channel-based failover mechanism of Flume, and the Flume Failover Sink Processor which switchs to a passive sink (if configured).

If Flume is able to solve them, maybe they should be WARN level (not sure, just a thought...)