Merge branch 'core-port' into add-nuspecs

Rx.NET/Source/NuGet.Config

@@ -2,8 +2,6 @@
 <configuration>
   <packageSources>
     <clear />
-    <add key="myget.org aspnetrc2" value="https://www.myget.org/F/aspnetrc2/api/v3/index.json" />        
-    <add key="xunit" value="https://www.myget.org/F/xunit/api/v3/index.json" /> 
     <add key="Build Packages" value="https://www.myget.org/F/c037199d-41df-4567-b966-25ff65324688/api/v3/index.json" />
     <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />    
   </packageSources>