Feature #1534: === Parameter handling ===
to associate units with parameters, use string instead of inheritance
|Status:||Archived||Start date:||03 Aug 2016|
While implementing units-in-parameters using the inheritance approach, I learned that units can be undefined when parameters are created, and must allow to be modified later. For instance when generic distributions is used in a specific context, mean value and standard deviation get their unit from that context. Complicated things also happen with detector coordinates. Probably, at some point we will want to pass unit as a parameter. All this can be handled much better if m_unit is a member variable of RealParameter. Easiest if that variable is of type string, m_unit = one of "", "nm", "rad". So I have to refactor, removing the inheritance mechanism implemented yesterday.