OS X support

[garrett]

Everything works fine on Linux... but for whatever reason, OS X isn't working.

The error message is "DocumentRoot must be a directory".

This error message leads me to believe that Docker on OS X might not support -v to map in a local directory to a container. If this is the case, then it might not be possible to get things working until it works upstream.

As OS X support is new to Docker, perhaps it's a bit unfinished or rough around the edges.

I would guess that this issue may affect Windows as well.