Gave History a face lift.

- Also refactored the internal actors a bit.
Fixing server project, furthur refactors
More refactors to server actors.

- Rename Calculation to StepAggregator.
Fixed demo project
Added toJson to history
Fixes dev project

- Moved creating a router to the Server responsibility. Allows for the ServerActor to remain private to the package, which is good for future refactors of the underlying Actor system.
Merge pull request #584 from lossyrob/topic/history

Gave History a face lift.