-Added IgnoreSerializableInterface to DefaultContractResolver

-Changed serializing ISerializable types under partial trust to error to fix security issue
-Fixed LinqBridge collision error in .NET 2.0 by moving types to a different namespace
-Fixed JObject.Keys error when object has no items

Src/Newtonsoft.Json/Serialization/JsonArrayContract.cs

@@ -25,10 +25,14 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Newtonsoft.Json.Utilities;
 using System.Collections;
+#if NET20
+using Newtonsoft.Json.Utilities.LinqBridge;
+#else
+using System.Linq;
+#endif
 
 namespace Newtonsoft.Json.Serialization
 {