Socket: Detect connection close

[Casper Færgemand" <shorttail at hotmail.com>]

Also, SocketStream: http://dlang.org/phobos/std_socketstream.html

> Warning: This module is considered out-dated and not up to 
> Phobos' current standards. It will remain until we have a 
> suitable replacement, but be aware that it will not remain long 
> term.

I wouldn't write any code using it.