Specify C# language version.

src/Renci.SshNet.NET35/Renci.SshNet.NET35.csproj

@@ -23,6 +23,7 @@
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <DocumentationFile>bin\Debug\Renci.SshNet.xml</DocumentationFile>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>none</DebugType>
@@ -927,7 +928,7 @@
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <ProjectExtensions>
     <VisualStudio>
-      <UserProperties ProjectLinkerExcludeFilter="\\?desktop(\\.*)?$;\\?silverlight(\\.*)?$;\.desktop;\.silverlight;\.xaml;^service references(\\.*)?$;\.clientconfig;^web references(\\.*)?$" ProjectLinkReference="2f5f8c90-0bd1-424f-997c-7bc6280919d1" />
+      <UserProperties ProjectLinkReference="2f5f8c90-0bd1-424f-997c-7bc6280919d1" ProjectLinkerExcludeFilter="\\?desktop(\\.*)?$;\\?silverlight(\\.*)?$;\.desktop;\.silverlight;\.xaml;^service references(\\.*)?$;\.clientconfig;^web references(\\.*)?$" />
     </VisualStudio>
   </ProjectExtensions>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 

src/Renci.SshNet/Renci.SshNet.csproj

@@ -23,7 +23,7 @@
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Debug\Renci.SshNet.xml</DocumentationFile>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-    <LangVersion>4</LangVersion>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>none</DebugType>