Add .sln compatible with Visual Studio 2013
Merge pull request #3866 from Dicebot/sln2013

Add .sln compatible with Visual Studio 2013
Revert "Add .sln compatible with Visual Studio 2013"
Merge pull request #3870 from eco/revert-3866-sln2013

Revert "Add .sln compatible with Visual Studio 2013"
Merge branch 'master' of https://github.com/D-Programming-Language/dmd