made eventmanager handle insertion of uuids into all events.

This facilitates backend agnostic support for multiple simulations in single output file/dbase.  Now backends don't have to each implement this themselves - and we have the guarantee that it is implemented consistently across all backends.  A full uuid is inserted into every row of every table.  It increases output data size by ~1.5x and doesn't have too much impact on simulation speed.

I also took the opportunity to remove the agents/agent-deaths consolidation from sqliteback.  It is a post processing operation and makes the sqlite backend database inconsistend with the schemas in other backends.  Since a great deal of post processing will be needed, we just as well keep it all together as a _post_ process.