Separated modules into subfolders with own setup.py

This restructuring allows for easier separation of modules into
separate repositories later. Also, now pip install with repo url can be
used.

The setup.py files have also been updated to correctly reference each
other. Module versions are not extracted from git state

pystencils_walberla_tests/test_walberla_gen.py

+import sympy as sp
+import pystencils as ps
+from pystencils_walberla import generate_sweep
+from pystencils_walberla.cmake_integration import ManualCodeGenerationContext
+
+try:
+    import pycuda
+except ImportError:
+    pycuda = None
+
+
+for openmp in (False, True):
+        for da in (False, True):
+            with ManualCodeGenerationContext(openmp=openmp, double_accuracy=da) as ctx:
+                h = sp.symbols("h")
+
+                dtype = "float64" if ctx.double_accuracy else "float32"
+
+                # ----- Jacobi 2D - created by specifying weights in nested list --------------------------
+                src, dst = ps.fields("src, src_tmp: {}[2D]".format(dtype))
+                stencil = [[0, -1, 0],
+                           [-1, 4, -1],
+                           [0, -1, 0]]
+                assignments = ps.assignment_from_stencil(stencil, src, dst, normalization_factor=4 * h**2)
+                generate_sweep(ctx, 'JacobiKernel2D', assignments, field_swaps=[(src, dst)])
+
+                # ----- Jacobi 3D - created by using kernel_decorator with assignments in '@=' format -----
+                src, dst = ps.fields("src, src_tmp: {}[3D]".format(dtype))
+
+                @ps.kernel
+                def kernel_func():
+                    dst[0, 0, 0] @= (src[1, 0, 0] + src[-1, 0, 0] +
+                                     src[0, 1, 0] + src[0, -1, 0] +
+                                     src[0, 0, 1] + src[0, 0, -1]) / (6 * h ** 2)
+
+                generate_sweep(ctx, 'JacobiKernel3D', kernel_func, field_swaps=[(src, dst)])
+
+                expected_files = ('JacobiKernel3D.cpp', 'JacobiKernel3D.h',
+                                  'JacobiKernel2D.cpp', 'JacobiKernel2D.h')
+                assert all(e in ctx.files for e in expected_files)
+
+                for file_name_to_test in ('JacobiKernel3D.cpp', 'JacobiKernel2D.cpp'):
+                    file_to_test = ctx.files[file_name_to_test]
+                    if openmp:
+                        assert '#pragma omp parallel' in file_to_test
+
+                    if da:
+                        assert 'float ' not in file_to_test
+                    else:
+                        assert 'double ' not in file_to_test

setup.py

+from setuptools import setup
+
+setup(name='pystencils_walberla',
+      description='pystencils code generation for waLBerla apps',
+      author='Martin Bauer',
+      license='AGPLv3',
+      author_email='martin.bauer@fau.de',
+      url='https://i10git.cs.fau.de/software/pystencils/',
+      packages=['pystencils_walberla'],
+      install_requires=['pystencils[alltrafos]', 'jinja2'],
+      package_data={'pystencils_walberla': ['templates/*']},
+      version_format='{tag}.dev{commits}+{sha}',
+      )