Merge branch 'TypeSystemRebase' into 'master'

.gitlab-ci.yml

conftest.py

doc/notebooks/01_tutorial_getting_started.ipynb

doc/notebooks/02_tutorial_basic_kernels.ipynb

doc/notebooks/06_tutorial_phasefield_dentritic_growth.ipynb

doc/sphinx/kernel_compile_and_call.rst

pystencils/__init__.py

pystencils/alignedarray.py

pystencils/assignment.py

pystencils/astnodes.py

pystencils/backends/cbackend.py

pystencils/backends/cuda_backend.py

pystencils/backends/cuda_known_functions.txt

pystencils/backends/simd_instruction_sets.py

pystencils/backends/x86_instruction_sets.py

pystencils/bit_masks.py

pystencils/boundaries/boundaryconditions.py

pystencils/boundaries/boundaryhandling.py

pystencils/boundaries/createindexlist.py

pystencils/boundaries/inkernel.py