implement Scene.GetSceneObjectGroup(UUID fullID) using existing index

OpenSim/Region/Framework/Scenes/Scene.cs

@@ -4278,6 +4278,16 @@ namespace OpenSim.Region.Framework.Scenes
         //            }
         //        }
 
+        /// <summary>
+        /// Get a group via its UUID
+        /// </summary>
+        /// <param name="fullID"></param>
+        /// <returns></returns>
+        public SceneObjectGroup GetSceneObjectGroup(UUID fullID)
+        {
+            return m_sceneGraph.GetSceneObjectGroup(fullID);
+        }
+
         /// <summary>
         /// Get a named prim contained in this scene (will return the first
         /// found, if there are more than one prim with the same name)

OpenSim/Region/Framework/Scenes/SceneGraph.cs

@@ -975,6 +975,22 @@ namespace OpenSim.Region.Framework.Scenes
             return result;
         }
 
+        /// <summary>
+        /// Get a group in the scene
+        /// </summary>
+        /// <param name="fullID">UUID of the group</param>
+        /// <returns>null if no such group was found</returns>
+        protected internal SceneObjectGroup GetSceneObjectGroup(UUID fullID)
+        {
+            lock (SceneObjectGroupsByFullID)
+            {
+                if (SceneObjectGroupsByFullID.ContainsKey(fullID))
+                    return SceneObjectGroupsByFullID[fullID];
+            }
+
+            return null;
+        }
+
         /// <summary>
         /// Get a part contained in this scene.
         /// </summary>