* Add support for 'template' in 'user_files'

* Fix-up wrong nesting level for template value

* Small quality improvement for push upstream.

* Consistency improvement for variable name

Fixes: 150

Previous example would result in quote escaping problem

in an attempt to save others from digging into the source (to confirm this detail)

This will allow users change their passwords after the initial setting in Salt.

Made both states configurable per user in pillar data
Had to drop extend, for this otherwise the extend would be empty if manage is
False

This adds the ability to manage the ~/.ssh/config file for users.

Example pillar:

ssh_keys:
  id_rsa:
    privkey: |
      -----BEGIN RSA PRIVATE KEY-----
      MIIEowIBAAKCAQEAoQiwO3JhBquPAalQF9qP1lLZNXVjYMIswrMe2HcWUVBgh+vY
      U7sCwx/dH6+VvNwmCoqmNnP+8gTPKGl1vgAObJAnMT623dMXjVKwnEagZPRJIxDy
      B/HaAre9euNiY3LvIzBTWRSeMfT+rWvIKVBpvwlgGrfgz70m0pqxu+UyFbAGLin+
      GpxzZAMaFpZw4sSbIlRuissXZj/sHpQb8p9M5IeO4Z3rjkCP1cxI
      -----END RSA PRIVATE KEY-----
    pubkey: |
      ssh-rsa MIIEowIBAAKCAQEAoQiwO3JhBquPAalQF9qP1lLZNXVjYMIswrMe2H....

had the prime group and ssh keys values as another dict. fixed.

Revising example pillar to add a minimal required values and a full
list of available values

Quick example of absent users