It combines the old IdentInterface with the ParamsInterface, providing an identifier and parameters (if needed).
The main purpose of the change is to make the class hierarchy (as viewed via doxygen) much easier to follow.
... Should have no effect on generated code, except perhaps some slight faster
virtual function calls. Mostly useful as documentation of design intent.
Tried to mark every one of our classes that inherits from another, or is a
base for others, or has abstract virtual functions, and a few others besides.
