It makes the code generation workflow more complicated without
contributing anything substantial

Instationary stuff not fixed so far.

The previous name was *really* confusing.

Much more telling name...

Now working apart from iteration order deterministicness

Useful, if you are only interested in the jacobian_apply versions
anyway.

It's completely unmaintained andI doubt that it will
at some point what it was intended for...

There is way more reasons to interpolate a function into the
solution vector and we cover them with one code path:
* Dirichlet boundary conditions (strong ones)
* Initial conditions for instationary expressions
* Initial guesses for Newton solvers