Send KillPackets on the Task queue rather than the State queue

Object updates are sent on the task queue.  It's possible for an object update to be placed on the client queue before a kill packet comes along.
The kill packet would then be placed on the state queue and possibly get sent before the update
If the update gets sent afterwards then client get undeletable no owner objects until relog
Placing the kills in the task queue should mean that they are received after updates.  The kill record prevents subsequent updates getting on the queue

Comments state that updates are sent via the state queue but this isn't true.  If this was the case this problem might not exist.

OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs

@@ -412,8 +412,14 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         /// <summary>
         /// Loops through all of the packet queues for this client and tries to send
-        /// any outgoing packets, obeying the throttling bucket limits
+        /// an outgoing packet from each, obeying the throttling bucket limits
         /// </summary>
+        /// 
+        /// Packet queues are inspected in ascending numerical order starting from 0.  Therefore, queues with a lower 
+        /// ThrottleOutPacketType number will see their packet get sent first (e.g. if both Land and Wind queues have
+        /// packets, then the packet at the front of the Land queue will be sent before the packet at the front of the
+        /// wind queue).
+        /// 
         /// <remarks>This function is only called from a synchronous loop in the
         /// UDPServer so we don't need to bother making this thread safe</remarks>
         /// <returns>True if any packets were sent, otherwise false</returns>