Minor fixes and separation of test cases and quicktests

pystencils/cpu/vectorization.py

pystencils/gpucuda/kernelcreation.py

pystencils/kernelcreation.py

pystencils/node_collection.py

pystencils/simp/assignment_collection.py

pystencils/transformations.py

pystencils/typing/__init__.py

pystencils/typing/cast_functions.py

pystencils/typing/leaf_typing.py

pystencils/typing/transformations.py

pystencils/typing/types.py

pystencils/typing/utilities.py

pystencils_tests/test_datahandling.py

pystencils_tests/test_loop_cutting.py

pystencils_tests/test_quicktests.py

pystencils_tests/test_simplification_strategy.py

setup.py