Add Load method to factory

Also update Initialize to take a path to the container

I also remove the initialProcess from the Initialize method. I think we could add this to the Config because it's an immutable option for the container ( the PID 1 ) and looks like it belongs there.  I'm not sure so let me know .

Closes #71

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)