minor: add some method doc to ScenePresence fields used for entity transfer, add minor details to some log messages, rename a misleading local variable name.

No functional changes.

OpenSim/Framework/ChildAgentDataUpdate.cs

@@ -287,6 +287,12 @@ namespace OpenSim.Framework
         public Vector3 AtAxis;
         public Vector3 LeftAxis;
         public Vector3 UpAxis;
+
+        /// <summary>
+        /// Signal on a V2 teleport that Scene.IncomingChildAgentDataUpdate(AgentData ad) should wait for the 
+        /// scene presence to become root (triggered when the viewer sends a CompleteAgentMovement UDP packet after
+        /// establishing the connection triggered by it's receipt of a TeleportFinish EQ message).
+        /// </summary>
         public bool SenderWantsToWaitForRoot;
 
         public float Far;