minor: Add some method doc to IMessageTransferModule

OpenSim/Region/Framework/Interfaces/IMessageTransferModule.cs

@@ -36,8 +36,26 @@ namespace OpenSim.Region.Framework.Interfaces
     {
         event UndeliveredMessage OnUndeliveredMessage;
 
+        /// <summary>
+        /// Attempt to send an instant message to a given destination.
+        /// </summary>
+        /// <remarks>
+        /// If the message cannot be delivered for any reason, this will be signalled on the OnUndeliveredMessage
+        /// event.  result(false) will also be called if the message cannot be delievered unless the type is
+        /// InstantMessageDialog.MessageFromAgent.  For successful message delivery, result(true) is called.
+        /// </remarks>
+        /// <param name="im"></param>
+        /// <param name="result"></param>
         void SendInstantMessage(GridInstantMessage im, MessageResultNotification result);
 
+        /// <summary>
+        /// Appropriately handle a known undeliverable message without attempting a send.
+        /// </summary>
+        /// <remarks>
+        /// Essentially, this invokes the OnUndeliveredMessage event.
+        /// </remarks>
+        /// <param name="im"></param>
+        /// <param name="result"></param>
         void HandleUndeliverableMessage(GridInstantMessage im, MessageResultNotification result);
     }
 }