Refactor: merge SceneGraph.AddScenePresence() into CreateAndAddChildScenePresence() since the former was only ever called from the latter

This allows us to remove dead code relating to adding root agents directly to the scenegraph, which never happens.

OpenSim/Region/Framework/Scenes/SceneGraph.cs

@@ -561,39 +561,15 @@ namespace OpenSim.Region.Framework.Scenes
         protected internal ScenePresence CreateAndAddChildScenePresence(
             IClientAPI client, AvatarAppearance appearance, PresenceType type)
         {
-            ScenePresence newAvatar = null;
-
             // ScenePresence always defaults to child agent
-            newAvatar = new ScenePresence(client, m_parentScene, appearance, type);
+            ScenePresence presence = new ScenePresence(client, m_parentScene, appearance, type);
-
-            AddScenePresence(newAvatar);
-
-            return newAvatar;
-        }
-
-        /// <summary>
-        /// Add a presence to the scene
-        /// </summary>
-        /// <param name="presence"></param>
-        protected internal void AddScenePresence(ScenePresence presence)
-        {
-            // Always a child when added to the scene
-            bool child = presence.IsChildAgent;
-
-            if (child)
-            {
-                m_numChildAgents++;
-            }
-            else
-            {
-                m_numRootAgents++;
-                presence.AddToPhysicalScene(false);
-            }
 
             Entities[presence.UUID] = presence;
 
             lock (m_presenceLock)
             {
+                m_numChildAgents++;
+
                 Dictionary<UUID, ScenePresence> newmap = new Dictionary<UUID, ScenePresence>(m_scenePresenceMap);
                 List<ScenePresence> newlist = new List<ScenePresence>(m_scenePresenceArray);
 
@@ -604,7 +580,7 @@ namespace OpenSim.Region.Framework.Scenes
                 }
                 else
                 {
-                    // Remember the old presene reference from the dictionary
+                    // Remember the old presence reference from the dictionary
                     ScenePresence oldref = newmap[presence.UUID];
                     // Replace the presence reference in the dictionary with the new value
                     newmap[presence.UUID] = presence;
@@ -616,6 +592,8 @@ namespace OpenSim.Region.Framework.Scenes
                 m_scenePresenceMap = newmap;
                 m_scenePresenceArray = newlist;
             }
+
+            return presence;
         }
 
         /// <summary>