Add editor settings files

https://visualstudiogallery.msdn.microsoft.com/410e9b9f-65f3-4495-b68e-15567e543c58
http://editorconfig.org/
Make projects open on Dev14

Project files should now work on any version of VS.
Microsoft.VisualStudio.TestPlatform.ObjectModel is now not copied to
output, so a single build should work on all VS versions
Fix unit test to check for current VS version