Template NEML objects on number type about neml

[reverendbedford]

So to resurrect this very dead issue:

Would being able to compile alternate versions of the library by doing something like:

#define Scalar double

be enough? Or do you really want the ability to template on the scalar type?

I intend to have everything done by the end of the summer where you can swap the scalar real type in a couple of places (the history/internal state system and the tensor math classes) and have that change propagate to the entirety of the library. We can think on what to do once that's done.

[dschwen]

Hm. I suspect we might only need dual numbers in very few places, with the mechanics Jacobians all being implemented fully. Let me think about this some more.