Add "debug lludp data out" console command for logging outgoing data just before it's put on the wire.

Unlike "debug lludp packet" which logs at the point where OpenSim first asks the clientstack to send a certain outgoing packet, this logs immediately before the actual send.
For low-level debugging purposes.

OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs

@@ -76,6 +76,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// or removed, this number must also change</summary>
         const int THROTTLE_CATEGORY_COUNT = 8;
 
+        /// <summary>
+        /// Controls whether information is logged about each outbound packet immediately before it is sent.  For debug purposes.
+        /// </summary>
+        /// <remarks>Any level above 0 will turn on logging.</remarks>
+        public int DebugDataOutLevel { get; set; }
+
         /// <summary>Fired when updated networking stats are produced for this client</summary>
         public event PacketStats OnPacketStats;
         /// <summary>Fired when the queue for a packet category is empty. This event can be