Use multi-TFM output directory for .NET Framework 4.0.

build/sandcastle/SSH.NET.shfbproj

@@ -41,8 +41,8 @@
       </ComponentConfig>
     </ComponentConfigurations>
     <DocumentationSources>
-      <DocumentationSource sourceFile="..\..\src\Renci.SshNet\bin\Release\Renci.SshNet.dll" xmlns="" />
-      <DocumentationSource sourceFile="..\..\src\Renci.SshNet\bin\Release\Renci.SshNet.xml" xmlns="" />
+      <DocumentationSource sourceFile="..\..\src\Renci.SshNet\bin\Release\net40\Renci.SshNet.dll" xmlns="" />
+      <DocumentationSource sourceFile="..\..\src\Renci.SshNet\bin\Release\net40\Renci.SshNet.xml" xmlns="" />
     </DocumentationSources>
     <MissingTags>Summary, Parameter, Returns, AutoDocumentCtors, TypeParameter, AutoDocumentDispose</MissingTags>
     <BuildAssemblerVerbosity>OnlyWarningsAndErrors</BuildAssemblerVerbosity>