Update nuget to v3.4

Author: xplicit

src/.nuget/NuGet.config

@@ -3,8 +3,15 @@
   <solution>
     <add key="disableSourceControlIntegration" value="true" />
   </solution>
+  <packageRestore>
+    <add key="enabled" value="True" />
+    <add key="automatic" value="True" />
+  </packageRestore>
   <packageSources>
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
     <add key="nuget.org" value="https://www.nuget.org/api/v2/" />
+    <add key="ServiceStack MyGet feed" value="https://www.myget.org/F/servicestack" />
   </packageSources>
+  <activePackageSource>
+    <add key="nuget.org" value="https://www.nuget.org/api/v2/" />
+  </activePackageSource>
 </configuration>

src/.nuget/NuGet.exe

@@ -12,7 +12,7 @@
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(OS)' != 'Windows_NT'">
-        <!-- We need to launch nuget.exe with the mono command if we're not on windows -->
+        <!-- We need to launch NuGet.exe with the mono command if we're not on windows -->
         <NuGetToolsPath>$(SolutionDir).nuget</NuGetToolsPath>
         <PackagesConfig>packages.config</PackagesConfig>
         <PackagesDir>$(SolutionDir)packages</PackagesDir>
@@ -53,7 +53,7 @@
     </PropertyGroup>
 
     <Target Name="CheckPrerequisites">
-        <!-- Raise an error if we're unable to locate nuget.exe  -->
+        <!-- Raise an error if we're unable to locate NuGet.exe  -->
         <Error Condition="!Exists('$(NuGetExePath)')" Text="Unable to locate '$(NuGetExePath)'" />
     </Target>
 
@@ -74,4 +74,4 @@
               LogStandardErrorAsError="true"
               Condition=" '$(OS)' == 'Windows_NT' " />
     </Target>
-</Project>
+</Project>