[SCons] Describe allowable values for msvc_version
[SCons] Describe allowable values for msvc_version

imitrichev/cantera,Heathckliff/cantera,Heathckliff/cantera,Heathckliff/cantera,Heathckliff/cantera,imitrichev/cantera,imitrichev/cantera,imitrichev/cantera,imitrichev/cantera,Heathckliff/cantera,imitrichev/cantera,Heathckliff/cantera