Check / cleanup inheritance

[borismarin]

In many of the ComponentType definitions, there are elements which are repeatedly defined in Parent types as well as in its children, see e.g.
https://github.com/NeuroML/NeuroML2/blob/development/NeuroML2CoreTypes/Networks.xml#L133
https://github.com/NeuroML/NeuroML2/blob/development/NeuroML2CoreTypes/Networks.xml#L144
https://github.com/NeuroML/NeuroML2/blob/development/NeuroML2CoreTypes/Networks.xml#L163

We need a list of which elements are being repeated, and why (should those fields be inherited or not?).

[borismarin]

This has reemerged with @andrisecker - <Text> elements are not inherited from parent comp types.
See LEMS/jLEMS#84
@andrisecker