Modified implementation to convert events into time series data

Review PR, do not merge yet.

Currently only instances are handled, however they are the only current event-based resource that we are currently collecting on and Borel is ready to handle at the moment.

Further modifications should be simple.

Processing logic has been separated from spooling to more easily facilitate testing

_event and _consolidated flags are added to consolidated sourcedicts to indicate the modified format. 

Do we need both? Is the presentation information in the consolidated version sufficient?

@glasnt @fractalcat