7017 - Add container pinning

Makes it so you can pass `--pin` to `docker run` so that you can't
`docekr rm` that container without also using `--force`
For example:

```
docker run -d -v /myData --pin --name my_data tianon/true
docker stop my_data # This isn't running, but for showcasing this, stop
it
docker rm my_data # this will fail even though it's not running
docker rm --force my_data # this will work
```

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)