Simplifies MSVC++ selection and setup. Also kills a bug where BUILD_WITH_MSVC could end up not being AC_SUBSTed.
Simplifies MSVC++ selection and setup. Also kills a bug where BUILD_WITH_MSVC could end up not being AC_SUBSTed.

Alexpux/SIMVoleon,Alexpux/SIMVoleon,Alexpux/SIMVoleon,Alexpux/SIMVoleon