In VS 2010 and above we support the [CMAKE_GENERATOR_TOOLSET](https://cmake.org/cmake/help/v3.6/variable/CMAKE_GENERATOR_TOOLSET.html) option to set the `<PlatformToolset>` element in generated `.vcxproj` files. However, we currently always use a flag map associated with the version of Visual Studio matching the generator in use (e.g. `cmVS14CLFlagTable.h`) instead of matching the specific toolset in use as MSBuild expects.