This will add more options to set to secure openssh
- AllowUsers
- AllowGroups
- DenyUsers
- DenyGroups

Correct indentation

When specifying multiple unknown ssh options, they would all appear on
the same line.

By not specifying it, root user's group should be used.

Synced file with default from Ubuntu 12.04 latest

This provides a default option (according to the package-provided config file) for each option in the config.

sshd_config

Current code was asking for service 'openssh' which does not exist. It is 'ssh'. Specifying a name in the `service.running` block fixes this.