Merge branch 'feature/costmodel-based-vectorization' into 'master'

applications/knl/poisson_dg/knl_poisson_dg.mini

applications/knl/poisson_dg/verify.mini

...ications/knl/poisson_dg_tensor/knl_poisson_dg_tensor.mini

applications/knl/poisson_dg_tensor/verify.mini

applications/poisson_dg/poisson_dg.mini

applications/poisson_dg/verify.mini

applications/poisson_dg_tensor/CMakeLists.txt

applications/poisson_dg_tensor/poisson_dg_tensor.mini

applications/poisson_dg_tensor/sliced/CMakeLists.txt

applications/poisson_dg_tensor/sliced/sliced.mini

applications/poisson_dg_tensor/verify.mini

applications/stokes_dg/stokes_dg.mini

python/dune/perftool/loopy/symbolic.py

python/dune/perftool/loopy/transformations/disjointgroups.py

python/dune/perftool/options.py

python/dune/perftool/pdelab/localoperator.py

python/dune/perftool/sumfact/accumulation.py

python/dune/perftool/sumfact/basis.py

python/dune/perftool/sumfact/permutation.py

python/dune/perftool/sumfact/realization.py