If a user moves back in sight of a child region before the agent has been closed on teleport, don't unnecessarily resend all avatar and object data about that region.

OpenSim/Framework/ISceneAgent.cs

@@ -65,6 +65,11 @@ namespace OpenSim.Framework
         /// </remarks>
         AvatarAppearance Appearance { get; set; }
 
+        /// <summary>
+        /// Set if initial data about the scene (avatars, objects) has been sent to the client.
+        /// </summary>
+        bool SentInitialDataToClient { get; }
+
         /// <summary>
         /// Send initial scene data to the client controlling this agent
         /// </summary>