Spawning a pty in D

[Adam D. Ruppe]

looking at the comments:

     //pragma(lib, "util"); // pragma does not work for me at 
moment. TODO: FIND OUT WHY!

If you are using gdc, and I think ldc too, that pragma is 
unsupported since it doesn't fit well into the gcc code - there's 
no easy way to pass linker flags from the D frontend to the gcc 
backend. So it is a dmd only thing right now.

Otherwise, pretty cool. Feel free to use anything of mine you 
want!