Does not clear the parent's attachment information when the child is deleted locally.
Either it was removed permanently, or just temporary - we don't know, but it's up to the server to send a *detach from child" packet for the parent.
What happened:
1) Object data is received. Client begins to read the data
2) Client initializes all its children (gob_cmd_update_infant)
3) Children try to attach to parent (yet not added)
4) Parent initializes, is added to the environment
And somewhere in between, Irrlicht wrecks up the attachments due to the missing matrix node.
The solution here is to:
1) Use the same structure as ServerActiveObject
2) Attach all children after the parent is really initialized
