Add a "LockedOut" flag to allow locking a region out via the grid server.

This flag prevents registration of a known region

OpenSim/Data/IRegionData.cs

@@ -71,6 +71,7 @@ namespace OpenSim.Data
         FallbackRegion = 2, // Regions we redirect to when the destination is down
         RegionOnline = 4, // Set when a region comes online, unset when it unregisters and DeleteOnUnregister is false
         NoDirectLogin = 8, // Region unavailable for direct logins (by name)
-        Persistent = 16 // Don't remove on unregister
+        Persistent = 16, // Don't remove on unregister
+        LockedOut = 32 // Don't allow registration
     }
 }

OpenSim/Services/GridService/GridService.cs

@@ -119,6 +119,9 @@ namespace OpenSim.Services.GridService
             
             if (region != null)
             {
+                if ((Convert.ToInt32(region.Data["flags"]) & (int)OpenSim.Data.RegionFlags.LockedOut) != 0)
+                    return false;
+
                 rdata.Data["flags"] = region.Data["flags"]; // Preserve fields
             }
             else