StrippedState feels weird

[erdnaxeli]

I am not sure about the StrippedState event. All others event have their own type, but StrippedState is a generic one and you have to check the type of its content (or check the "type" field) to know what it is.

Maybe we should use a macro to generate Stripped version of all existing state event. They would have the same fields as StrippedState, but with their correct content (instead of this ad-hoc method).

And with this they could inherite from StateEvent, like other state events.