* Enabled dead region tracking for ChildAgentDataUpdates

** If the region fails 3 times, then ChildAgentDataUpdates no longer get sent to that region
* Enabled Child_Get_Tasks in grid mode.   
* When Child_Get_Tasks is enabled on neighbor regions, the neighbor region uses the client's draw distance to send out prim.   This is a lot less likely to flood the client now since the ChildAgentDataUpdate contains both the throttle settings and the draw distance.   This means that with this enabled, you can see prim in other regions in grid mode.   Very experimental.

OpenSim/Region/Examples/SimpleApp/MyNpcCharacter.cs

@@ -226,7 +226,12 @@ namespace SimpleApp
         public virtual void SetChildAgentThrottle(byte[] throttle)
         {
         }
+        public byte[] GetThrottlesPacked(float multiplier)
+        {
+            return new byte[0];
+        }
 
+        
         public virtual void SendAnimations(LLUUID[] animations, int[] seqs, LLUUID sourceAgentId)
         {
         }