Try again to fix 'make dist'
It turns out that we must put Directory.Build.props in win32/vs10 and let automake copy it over to win32/vs15/... so do that, and only dist the copy in win32/vs15.
It turns out that we must put Directory.Build.props in win32/vs10 and let automake copy it over to win32/vs15/... so do that, and only dist the copy in win32/vs15.