You should now see the correct Avatar for other users, including their clothes, although their still seems to be a few problems with the clothes, in that sometimes other avatar's default clothes are white.

At last, removed the need for the avatar-texture.dat file. (Please never come back).

OpenSim/Region/Examples/SimpleApp/MyNpcCharacter.cs

@@ -119,6 +119,7 @@ namespace SimpleApp
 
         public virtual void OutPacket(Packet newPack) { }
         public virtual void SendWearables(AvatarWearable[] wearables) { }
+        public virtual void SendAppearance(LLUUID agentID, byte[] visualParams, byte[] textureEntry) { }
         public virtual void SendStartPingCheck(byte seq) { }
         public virtual void SendKillObject(ulong regionHandle, uint avatarLocalID) { }
         public virtual void SendAnimation(LLUUID animID, int seq, LLUUID sourceAgentId) { }