make it possible to use setup.py without having an installed dune-common...

make it possible to use setup.py without having an installed dune-common python package. This requires having the PYTHONPATH set as it is now done in dune-common/bin/dunepackaging.py

.gitignore

 *~
 /build*/
+# ignore files generated during python setup.py sdist
+MANIFEST
+_skbuild/
+dist

dune-istl.pc.in

@@ -8,8 +8,8 @@ DEPENDENCIES=@REQUIRES@
 
 Name: @PACKAGE_NAME@
 Version: @VERSION@
-Description: Dune (Distributed and Unified Numerics Environment) istl module
-URL: http://dune-project.org/
+Description: @DESCRIPTION@
+URL: @URL@
 Requires: ${DEPENDENCIES}
 Libs:
 Cflags: -I${includedir}

dune.module

 Module: dune-istl
 Version: 2.8-git
+Author: The Dune Core developers
 Maintainer: dune-devel@lists.dune-project.org
+Description: Iterative solver template library which provides generic sparse matrix/vector classes and a variety of solvers based on these classes
+URL: https://gitlab.dune-project.org/core/dune-istl
+Python-Requires:
 Depends: dune-common (>= 2.8)
 Whitespace-Hook: Yes

pyproject.toml

+[build-system]
+requires = ['setuptools', 'wheel', 'scikit-build', 'cmake', 'ninja', 'requests', 'dune-common>=2.8.0.dev0']
+build-backend = 'setuptools.build_meta'

python/setup.py.in

 from setuptools import setup, find_packages
 
-setup(name="dune.istl",
+pkg = [m for m in "${ProjectPythonRequires}".split(' ') if "dune" not in m]
+
+setup(name="${ProjectName}",
     namespace_packages=['dune'],
-    description="Python lib for dune: dune-alugrid library",
-    version="${DUNE_ISTL_VERSION}",
-    author="Andreas Dedner and Martin Nolte",
+    description="${ProjectDescription}",
+    version="${ProjectVersionString}",
+    author="${ProjectAuthor}",
+    author_email="${ProjectMaintainerEmail}",
     packages = find_packages(),
     zip_safe = 0,
-    package_data = {'': ['*.so']}
+    package_data = {'': ['*.so']},
+    install_requires = pkg
   )

setup.py

+try:
+    from dune.packagemetadata import metaData
+except ImportError:
+    from packagemetadata import metaData
+from skbuild import setup
+setup(**metaData()[1])