Update compiler flags for MSVC
Update compiler flags for MSVC

Luthaf/Chemharp,lscalfi/chemfiles,chemfiles/chemfiles,chemfiles/chemfiles,Luthaf/Chemharp,chemfiles/chemfiles,Luthaf/Chemharp,lscalfi/chemfiles,chemfiles/chemfiles,lscalfi/chemfiles,lscalfi/chemfiles