imported signalr 1.1.3 into NzbDrone.

src/Microsoft.AspNet.SignalR.Core/Infrastructure/DiffPair.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.md in the project root for license information.
+
+using System.Collections.Generic;
+
+namespace Microsoft.AspNet.SignalR.Infrastructure
+{
+    internal struct DiffPair<T>
+    {
+        public ICollection<T> Added;
+        public ICollection<T> Removed;
+
+        public bool AnyChanges
+        {
+            get
+            {
+                return Added.Count > 0 || Removed.Count > 0;
+            }
+        }
+    }
+}