create MANIFEST.in if "setup.py install" is used
create MANIFEST.in if "setup.py install" is used

this fixes the issue that the non-python files are not included when the package is installed and the wheel package is not available

MSLNZ/msl-loadlib,MSLNZ/msl-loadlib,MSLNZ/msl-loadlib,MSLNZ/msl-loadlib,MSLNZ/msl-loadlib