make Pid constructor public

[Steven Schveighoffer]

On Mon, 17 Jun 2013 18:38:34 -0400, Timothee Cour  
<thelastmammoth at gmail.com> wrote:

> inside std.process it says:
> // Pids are only meant to be constructed inside this module, so we make  
> the
> constructor private.
> However, this makes a number of useful functions from std.process useless
> unless the processes were created via one of std.process' functions.
> Can we make std.process.Pid.this(int pid) public?

Not a bad idea.  In fact, I think we were toying with possibly having ways  
to obtain Pids from the OS.  This would be an interim step.

-Steve