Note that Docker 1.0 (and the brief 0.12.0) changed its TCP port from 4243 to 2375. If you use a remote client (like `brew install docker`) and have `DOCKER_HOST=4243` in your environment, you'll have to update it.

To ease this pain across a large team, I'm considering using netfilter/iptables or a TCP proxy to make the old port available in our VM environment during transition.

https://github.com/dotcloud/docker/commit/5febba93babcf8c4b0...