Do a better event re-injection and fix quotes in CKAN attrValues

This PR implements the issue https://github.com/telefonicaid/fiware-connectors/issues/52 which has been shown in https://github.com/telefonicaid/fiware-connectors/issues/103 (opened) and https://github.com/telefonicaid/fiware-connectors/issues/123 (closed)

This PR also fixes the issue described at https://github.com/telefonicaid/fiware-connectors/issues/106 (opened)
I see big block of changes in all backend classes hard to follow... 

As far as I checked, the changes are mostly related with exception capturing and throwing. Is that correct or there are other relevant changes that worth the time to review?