Moved Frame models, added default providers

src/Discord.Net.Rest/Net/DefaultRestClientProvider.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace Discord.Net.Rest
+{
+    public static class DefaultRestClientProvider
+    {
+        public static readonly RestClientProvider Instance = url => 
+        {
+            try
+            {
+                return new DefaultRestClient(url);                    
+            }
+            catch (PlatformNotSupportedException ex)
+            {
+                throw new PlatformNotSupportedException("The default RestClientProvider is not supported on this platform.", ex);
+            }
+        };
+    }
+}