- Removing unneeded `CashBook` instance to create a new `TimeSlice`
- Adding new `TimeSliceFactory`, an instance base class that will
provide methods to create a new `TimeSlice`. Will own the `DateTimeZone`
property.
- Adding new `ISecurityPrice` and `IOptionPrice` that will provide a
reduced interface for accessing price properties and methods used when
creating a new `TimeSlice`
- Completly move `DataManager` in front of `DataFeed`. Specifically
`AddSubscription()` and `RemoveSubscription()` implementations. Also
removing IDataFeed.Subscriptions
- Creating new `Synchronizer` which will consolidate and combine `TimeSlice`
streaming for both live and backtests modes. Will live in front of the
`DataManager`
- `SubscriptionSynchronizer` will be the `FrontierTimeProvider` exposed,
and owned, by the new `Synchronizer`
- Updating existing tests