Stop & Kill options for containers removal

Closes #6533

**docker rm**:
`-f/--force`: deprecation warning.
`-s/--stop`: stop then remove a container.
`-k/--kill`: kill then remove a container

**API**:
`DELETE /containers/(id)`
`DELETE /containers/(name)`

`force`: stop then remove a container.
`kill`: kill then remove a container.
`/redis` is not the container you think it is. If I have named a container `docker run --name redis ...`, then you will need to use `docker rm --stop redis`.

sadly, typing `docker rm --stop /redis` will return `/redis` but not do anything to the `redis` container

and typing `docker run --name /redis` will also happily name your container `redis`

```
docker(master) $ docker run -d --name /redis busybox top
f72aefcda915b4c9545aa3d9128064815cf0a2af7c20a85fd1f229a0bb30e30e
docker(master) $ docker ps
CONTAINER ID        IMAGE                      COMMAND                CREATED             STATUS              PORTS                     NAMES
f72aefcda915        busybox:latest             top                    4 seconds ago       Up 3 seconds                                  redis            
```

so please, remove all the `/` from your `/redis` uses.