It does not yet do all the jobs it can do, but it exists and we can
run tests with it.

by introducing an order on the kernel objects and
using the first n kernels instead of an itertools.permutations
generator

We will need even more "levels" in the near future

for further extension

So far, it did not set the qp tuple correctly and
thus sometimes resulted in too big numbers being
chosen.

Feature/undo tensor sum fix

See merge request dominic/dune-perftool!224

Coefficient evaluation

Closes #107

See merge request dominic/dune-perftool!222

This reverts commit 5081753a.

In that case you need two GridFunctions, which can be
bound to the two cells.

Also allow the usage of the __static section (as known from dune-testtools).
However, variation in the static section is not yet considered!

Needs monkey patching of the preprocessing to not
transfer to reference element...

After consulting Steffen