Add partial support docker v1.6 api

This PR Introduce a new state ```docker.running```.
    
Before ```docker.installed``` was also starting the container.
It was too hard to make it work properly, and break salt philosophy: KISS.
    
This PR introduce non backward compatible changes, and requires docker-py that is not yet released on pypi :angry: . (I'm using the master of the project the time I wrote this changeset.)

Thus, I'm not sure it is ready to be merged in this state.

Please, can you review the PR  ? also pay more attention to the mod_watch implementation, I'm not sure I did it correctly.

Thx.