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/Framework/General/NullClientAPI.cs

@@ -104,6 +104,7 @@ namespace OpenSim.Framework
 
        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){}