Set container name and allow adding of arguments to docker run

I wanted to link containers with the 0.6.5 release and this is how I got about it. Added an `args` command that lets you specify additional arguments to do on docker run. So for example I could do:

```bash
$ stevedore args env "-link redis:redis -link mysql:mysql"
$ stevedore args env
-link redis:redis -link mysql:mysql
$ stevedore rebuild env
```

Also added names since well, we can do so now :D