preconditioner, i.e. set new linearization point.

[feature][InvHelmholtzOp] Added inverse DGHelmholtzOperator

See merge request !42

gridPart does not have a gridView argument anymore

See merge request !44

exported and used on Python side for RungeKutta solvers such that these
can be used in parallel.

refactor the way python is used in dune

See merge request !32

replace assertHave with assertCMakeHave which has to be used slightly differently with the new dune-py setup process

adapt ci yml file to python bindings on by default

pep 42: use implicit namespace packages which make it possible to combine subpackages using editable (source) and non editable (pypi)

simplified ci based on new python binding setup in dune-common

check if mpi4py is needed to fix CI

add a stopgap solution unti ci repo up and running again

only add dune modules that have been found as requirements in setup.py.in

removed setup.py.in since the default is provided in dune-common

of dim.

tutorial.

Threading of GalerkinOperator.

See merge request !34

API changes:

See merge request !39