Add more common docker commands to context menu

e.g.

* `docker run -it [thingy] /bin/bash` (ideally user-configurable) to quickly run a shell command inside the container
* remove container (and remove image, once #2 comes around),
* stop/start multiple containers (currently it's only one at a time)
* view logs of a container (both ad-hoc and tailing)

I'm sure there are a bunch more that people will find useful.