Several updates for shard - no BC breaks

* Add Exception Event Aggregator. Now, when there is an exception like event called, the agregator will catch all of them and raise an `exception` event. This means you only need to subscribe to one event, rather than lots, to see what might have gone wrong in a flush.
* Add test/example for multiple connections
* Add more `encryptField` and `decryptField` to crypt helper.