Remove syncpipe pkg

This removes the entire syncpipe package and replaces it with standard
operations on the pipes.  The syncpipe type just never felt right and
probably should not have been there.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
I'll have to look back at the commit log, I think we wanted to set an extra flag that is not on `os.Pipe`