Move PushStreamContent Namespace (#467)

* Move PushStreamContent Namespace

Previous behavior caused issues of �mbiguous reference around
PushStreamContent when both Refit and System.Net.Http.Formatting are
included in a project. This is essentially a show stopper to upgrading
to the latest Refit.

The solution is to change the internal implementation of PushStreamContent
namespace from System.Net.Http -> Refit.Net.Http and to update
the usages internally. Note this may be a breaking change to those who
have taken a dependency on PushStreamContent in their own projects from
the Refit assemblies.

* Make types internal

Refit.Tests/RefitStubs.Net46.cs

@@ -391,11 +391,19 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task NothingToSeeHere()
+        public virtual Task<User> NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = methodImpls.GetOrAdd("NothingToSeeHere()", _ => requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  }));
-            return (Task)func(Client, arguments);
+            return (Task<User>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
+        {
+            var arguments = new object[] {  };
+            var func = methodImpls.GetOrAdd("NothingToSeeHereWithMetadata()", _ => requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHereWithMetadata", new Type[] {  }));
+            return (Task<ApiResponse<User>>)func(Client, arguments);
         }
 
         /// <inheritdoc />

Refit.Tests/RefitStubs.NetCore2.cs

@@ -391,11 +391,19 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task NothingToSeeHere()
+        public virtual Task<User> NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = methodImpls.GetOrAdd("NothingToSeeHere()", _ => requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  }));
-            return (Task)func(Client, arguments);
+            return (Task<User>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
+        {
+            var arguments = new object[] {  };
+            var func = methodImpls.GetOrAdd("NothingToSeeHereWithMetadata()", _ => requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHereWithMetadata", new Type[] {  }));
+            return (Task<ApiResponse<User>>)func(Client, arguments);
         }
 
         /// <inheritdoc />

Refit/PushStreamContent.cs

@@ -23,9 +23,11 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Contracts;
 using System.IO;
+using System.Net;
 using System.Net.Http.Headers;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Net.Http;
 
 namespace System.Net.Http
 {
@@ -36,7 +38,7 @@ namespace System.Net.Http
     /// </summary>
     // https://github.com/ASP-NET-MVC/aspnetwebstack/blob/d5188c8a75b5b26b09ab89bedfd7ee635ae2ff17/src/System.Net.Http.Formatting/PushStreamContent.cs
     [ExcludeFromCodeCoverage]
-    public class PushStreamContent : HttpContent
+    class PushStreamContent : HttpContent
     {
         private readonly Func<Stream, HttpContent, TransportContext, Task> _onStreamAvailable;
 
@@ -182,7 +184,7 @@ protected override void Dispose(bool disposing)
     /// </summary>
     // https://github.com/ASP-NET-MVC/aspnetwebstack/blob/d5188c8a75b5b26b09ab89bedfd7ee635ae2ff17/src/System.Net.Http.Formatting/Internal/DelegatingStream.cs
     [ExcludeFromCodeCoverage]
-    internal abstract class DelegatingStream : Stream
+    abstract class DelegatingStream : Stream
     {
         Stream innerStream;