* Fix trade drawdown calculation
* Cleanup
* Disable MAE. MFE and Drawdown calculation for FlatToFlat and FlatToReduced trade grouping methods
* Minor test fixes
- Revert charting rouding
- Add statistics rouding
- Json converter will ignore null order values
- Remove `type` field in `Symbol` json
- Add default type value for the `TimeInForceJsonConverter`
Added Trade and TradeBuilder classes
Added UtcTime and OrderFee property to OrderEvent class
Added AlgorithmPerformance class with a few metrics + tests
Added portfolio statistics + rolling statistics
Closes#30 via PR #164
Thanks @SteffanoRaggi!