This is the wrong approach for detached mode, which we want to use to
minimize race conditions by getting the container ID from Docker immediately.
The detached approach will also work better if/when we reimplement the
DockerAPI class by using the Docker API.
Looks like we got ourselves a lifetime.
Forgot these files earlier. :(  The wrong-approach file was assuming we'd
stay attached; because we get the container ID back immediately when running
detached, we thought it might work a little better.
Update the TODOs in the code.  Moved some notes from comments to docker-notes.  Like docker-api.cpp.wrong-approach, should be removed before squash-and-merge.