- 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`
Martin Molinero