Fixes: #471 Can't build in VS 2015

Fixes #471 due to missing Microsoft.VisualBasic.dll assembly, and after that an invalid reference to Microsoft.Research/Contracts/MsCorlib/MsCorlib.Contracts.csproj.

Microsoft.Research/Contracts/Contracts.sln

@@ -3,7 +3,7 @@ Microsoft Visual Studio Solution File, Format Version 10.00
 # Visual Studio 2008
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tools", "Tools\Tools.csproj", "{F3259C18-92B3-4C24-ABFD-1B57BAFFDA95}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MsCorlib.Contracts", "MsCorlib\MsCorlib.Contracts.csproj", "{D45E4F81-3252-4000-9818-F8D018895B5B}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MsCorlib.Contracts", "MsCorlib\MsCorlib.Contracts10.csproj", "{D45E4F81-3252-4000-9818-F8D018895B5B}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "System.Contracts", "System\System.Contracts.csproj", "{2C10FDB2-966D-4A14-B18D-385FDFA1746A}"
 EndProject