Add the RegionLoaded(Scene) API to the new region module interface to allow

region modules to use another region module's interfaces and events in
a scene context

OpenSim/ApplicationPlugins/RegionModulesController/RegionModulesControllerPlugin.cs

@@ -174,6 +174,26 @@ namespace OpenSim.ApplicationPlugins.RegionModulesController
                 module.AddRegion(scene);
                 scene.AddRegionModule(module.Name, module);
             }
+
+            // This is needed for all module types. Modules will register
+            // Interfaces with scene in AddScene, and will also need a means
+            // to access interfaces registered by other modules. Without
+            // this extra method, a module attempting to use another modules's
+            // interface would be successful only depending on load order,
+            // which can't be depended upon, or modules would need to resort
+            // to ugly kludges to attempt to request interfaces when needed
+            // and unneccessary caching logic repeated in all modules.
+            // The extra function stub is just that much cleaner
+            //
+            foreach (ISharedRegionModule module in m_sharedInstances)
+            {
+                module.RegionLoaded(scene);
+            }
+
+            foreach (INonSharedRegionModule module in list)
+            {
+                module.RegionLoaded(scene);
+            }
         }
 
         public void RemoveRegionFromModules (Scene scene)

OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs

@@ -136,6 +136,10 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             LoadPlugins();
         }
 
+        public void RegionLoaded(Scene scene)
+        {
+        }
+
         public void RemoveRegion(Scene scene)
         {
             lock (m_scene)

OpenSim/Region/Framework/Interfaces/IRegionModuleBase.cs

@@ -71,6 +71,19 @@ namespace OpenSim.Region.Framework.Interfaces
         /// A <see cref="Scene"/>
         /// </param>
         void RemoveRegion(Scene scene);
+
+        /// <summary>
+        /// This will be called once for every scene loaded. In a shared module
+        /// this will be multiple times in one instance, while a nonshared
+        /// module instance will only be called once.
+        /// This method is called after AddRegion has been called in all
+        /// modules for that scene, providing an opportunity to request 
+        /// another module's interface, or hook an event from another module.
+        /// </summary>
+        /// <param name="scene">
+        /// A <see cref="Scene"/>
+        /// </param>
+        void RegionLoaded(Scene scene);
     }
 
 }