[RFC][PATCH 7/8]: Auto-create ptmx node when mounting devpts

[Alan Cox]

> auto-created, than supporting mknod(2) inside the devpts filesystem. 
> It's not a matter of "changing the user space"; it's a matter of what 
> makes most sense inside the kernel.

Having an extra node with different permissions suddenely appear without
warning isn't I think good behaviour. I'm open to being convinced and the
other problems with that code are more pressing.