Merge branch 'feature/new-istl-linear-solvers-rebased' into 'master'

dumux/assembly/fvassembler.hh

dumux/linear/amgbackend.hh

dumux/linear/istlsolverfactorybackend.hh

dumux/linear/istlsolvers.hh

dumux/linear/linearalgebratraits.hh

dumux/linear/linearsolveracceptsmultitypematrix.hh

dumux/linear/linearsolverparameters.hh

dumux/linear/linearsolvertraits.hh

dumux/linear/parallelhelpers.hh

dumux/linear/seqsolverbackend.hh

dumux/linear/solver.hh

dumux/linear/solvercategory.hh

dumux/multidomain/fvassembler.hh

dumux/nonlinear/newtonsolver.hh

examples/biomineralization/doc/mainfile.md

examples/biomineralization/main.cc

test/freeflow/navierstokes/donea/CMakeLists.txt

test/freeflow/navierstokes/donea/main.cc

test/freeflow/navierstokes/donea/main_momentum.cc

test/freeflow/navierstokes/kovasznay/main.cc