Enable runtime configuration of the minimum rate for adaptive

throttles. Setting adaptive_throttle_min_bps will change the
minimum rate that the adapative throttles will drop to in case
of network packet loss. The current rate default rate is 256kbps.
The viewer can throttle rates under that amount, but the dynamic
adaptation will not.

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

@@ -58,7 +58,14 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         /// <summary>Flag used to enable adaptive throttles</summary>
         public bool AdaptiveThrottlesEnabled;
-        
+ 
+        /// <summary>
+        /// Set the minimum rate that the adaptive throttles can set. The viewer
+        /// can still throttle lower than this, but the adaptive throttles will
+        /// never decrease rates below this no matter how many packets are dropped
+        /// </summary>
+        public Int64 MinimumAdaptiveThrottleRate;
+ 
         /// <summary>Amount of the texture throttle to steal for the task throttle</summary>
         public double CannibalizeTextureRate;
 
@@ -84,7 +91,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 Total = throttleConfig.GetInt("client_throttle_max_bps", 0);
 
                 AdaptiveThrottlesEnabled = throttleConfig.GetBoolean("enable_adaptive_throttles", false);
-                
+                MinimumAdaptiveThrottleRate = throttleConfig.GetInt("adaptive_throttle_min_bps", 32000);
+
                 CannibalizeTextureRate = (double)throttleConfig.GetFloat("CannibalizeTextureRate", 0.0f);
                 CannibalizeTextureRate = Util.Clamp<double>(CannibalizeTextureRate,0.0, 0.9);
             }