[WIP] Install smbclient dependencies to enable SMB/CIFS External storage

[xtrasimplicity]

I've simply added smbclient as a dependency to each Dockerfile (using the templates, of course), to allow SMB/CIFS shares to be used under the External Storage configuration.

[tilosp]

See: #22

[xtrasimplicity]

Ahh, thanks @tilosp. I must admit, I didn't see the . examples folder until after I submitted this PR.

Would it be worth adding some of the example dockerfiles, or at least the full example, to Docker Hub, as well?