Some additional renaming. A few that were missed before.
Also since the API changes creeped into so much code,
decided to just go ahead and change the remaining code. #624

CamelCase types and names converted to under_score names and types. #624

-Add startup verification of no data

- Now collections are dropped instead of database since
  databaes drop requires additional privileges that the
  user may not have.

-Add MongodB URI command line option
-Add exception handling of process_irreversible_block
-Add verification of last block on startup