title: Getting project, solution files for different versions of Visual Studio
body: <p>I have a suite of C++ programs in Visual Studio 2012.  I want to provide project and solution files for Visual Studio 2013 and 2015 as well (and later versions as they come), in the appropriate subfolders.  </p>
  
  <p>Is there a way to get Visual Studio to <em>leave</em> the old project and solution files, while adding the new ones?  </p>