Introduce default assignment simplifications

There are many simplifications in pystencils that are usually not applied. They can be applied now by using a simple argument in the configuration.

Fixes #39 (closed)

.gitlab-ci.yml

@@ -254,8 +254,13 @@ pycodegen-integration:
     - pip install -e pystencils/
     - pip install -e lbmpy/
     - pip install -e pygrandchem/
-    - ./install_walberla.sh
     - export NUM_CORES=$(nproc --all)
+    - cd walberla
+    - mkdir build || true
+    - cd build
+    - cmake --version
+    - cmake -DWALBERLA_BUILD_WITH_PYTHON=1 -DWALBERLA_BUILD_WITH_CUDA=1 -DWALBERLA_OPTIMIZE_FOR_LOCALHOST=1 -DWALBERLA_BUILD_WITH_CODEGEN=1 -DPython_EXECUTABLE=/opt/conda/envs/pystencils_dev/bin/python3.8 ..
+    - make -j ${NUM_CORES} pythonModuleInstall
     - mkdir -p ~/.config/matplotlib
     - echo "backend:template" > ~/.config/matplotlib/matplotlibrc
     - cd pystencils