docker-common installs a script at /usr/bin/docker which will point to
/usr/bin/docker-current by default. The docker daemon user could set the
DOCKERBINARY variable in /etc/sysconfig/docker to point this to
/usr/bin/docker-latest instead.

It also installs an hourly cron job to cleanup dead containers. This job will
not run if neither docker nor docker-latest is running.