Create the ability for physics modules to request assets on demand by

themselves. For that, the physics module simply calls RequestAssetMethod, which
in turn points to Scene.PhysicsRequestAsset. This gives physics access to
the asset system without introducing unwanted knowledge of the scene class.

OpenSim/Region/Application/OpenSimBase.cs

@@ -700,6 +700,7 @@ namespace OpenSim
             scene.LoadWorldMap();
 
             scene.PhysicsScene = GetPhysicsScene(scene.RegionInfo.RegionName);
+            scene.PhysicsScene.RequestAssetMethod = scene.PhysicsRequestAsset;
             scene.PhysicsScene.SetTerrain(scene.Heightmap.GetFloatsSerialised());
             scene.PhysicsScene.SetWaterLevel((float) regionInfo.RegionSettings.WaterHeight);