* Use consistent Jinja whitespace control `{%- ... -}`
* Improve debug output (comments & whitespace control)
* Use exact state names with TOFS `files_switch`
* Add `ssh_known_hosts_src` to `defaults` (for consistency)
* Restrict `pillar.example` changes to TOFS only
* Use `fire_banner` in `pillar.example` to indicate available template

This state manages /etc/ssh/ssh_known_hosts and fills it with
public SSH host keys of other minions.