bug#3736: 23.1.50; Please use null-device instead of /dev/null

[Jason Rumney]

Michael Albinus wrote:

> On W32 systems, null-device is "NUL". Not useful for Tramp, it needs
> "/dev/null" on remote machines.
>   

What if the remote machine uses "NUL", "NLA0:" or "Dev:Nul" for its null 
device? I think tramp benefits from the use of null-device instead of 
hard-coded "/dev/null" as much as any other part of Emacs.