still allow people to override them in defaults.yml

use the world-wide pool by default, but specify north-america in
user.yml. Also, documentation. This way Sovereign will still behave the
same, but the NTP servers can be changed when desired.

Remove all configuration for MySQL and configure PostgreSQL as the main
database.

All *_mysql_* options have been changed to *_db_* options.

Postgres requires the database user to have a password in order to
connect via localhost. The db_admin_password option is used to set the
password of the admin user (usually postgres).

Signed-off-by: PajamaSoft <support@pajamasoft.com>

Use the changed `mail_virtual_users` structure to ensure directories and
sieve rules are created for each defined account.

correctly. The number of days that a certificate will be considered
valid is now a user-controlled variable and is set to five years by
default. (Fixes Issue #87)

 * Add an openvpn_server variable
 * Move ${openvpn_client}.{key,csr,crt} to
   ${openvpn_client}/client.{key,csr,crt}
 * Generate ${openvpn_client}/${openvpn_server}.ovpn config file
 * Copy over a self contained directory of file per client that can be
   imported by networkmanager in ubuntu or run directly with `sudo
   openvpn ${openvpn_server}.ovpn

Add server_ip_address to vars/user.yml

  * OpenVPN setup is now fully automated. No configuration changes
    are necessary (though the defaults can easily be modified) and
    all manual command line steps have been eliminated.

  * Removed the dependency on easy-rsa in favor of pure OpenSSL and
    OpenVPN commands that are executed by Ansible

  * Improved the security of the OpenVPN configuration
    * Increased the default key size to 2048
    * RSA keys are only readable by root
    * The cipher and authentication digest are now configurable. If
      your client supports it, you can use AES-256-CBC and SHA256
      instead of BF-CBC (Blowfish) and SHA1 which are the defaults.
      Or you can be a really cool, paranoid, crypto hipster and
      use CAMELLIA-256-CBC and SHA512 with an RSA key size of 4096.
    * Enabled "HMAC firewall" functionality using the tls-auth option
      and automated the generation of the 'ta' key that it depends on
    * The OpenVPN daemon becomes an unprivileged user after it starts

  * Automated the retrieval of the files that clients will need in
    order to connect to OpenVPN

  * A pause prompt outputs basic configuration information after the
    role has finished running

  * Variables are referenced using the new Ansible variable format
    (e.g. {{ var }} instead of $var)

  * Added a flush_handlers command to the role that ensures OpenVPN
    will restart prior to dnsmasq (fixes issue #63)

  * Fixed two bugs that were preventing packet forwarding for IPv4
    from being enabled correctly

That way it's more convenient to uncomment an entire paragraph.

Refs #39

That way the default values will not be applied by mistake. The user
needs to uncomment the lines from `vars/users.yml` and set them.

Also renamed openvpn variables.

Refs #39

That way we can override all the config from a central location. The
`user.yml` file overrides `defaults.yml`. `user.yml` was added to
`.gitignore` in order to allow a user to change it without having to
worry about merges. It's easy to do a diff to see what changed between
the defaults and your own settings.

Needs documentation, this is just a proposal.

Refs #39