A module (cli.py) is used to provide an entry point for the msspec
package. It is here to be PEX-compatible (https://github.com/pantsbuild/pex)
that may be used to provide a zero-install msspec distribution.
The version is now not hardcoded anymore in the python module. We use
setuptools_scm or pkg_resources instead.
There was also a bug in the linkage for PED with matrix inversion using
external lapack.
Finally, the install script install now requirements and all requirements
are stored in the requirements.txt file. setup.py looks inside to set its
"install_requires" keyword.
Sylvain Tricot