Set individual variables for each cert

Allow a different cert for each host, defaulting to the same wildcard
cert.
Copy the mail cert

If the mail cert is not the same as the wildcard ssl cert, then move it
into place, otherwise do nothing as the wildcard ssl cert will be used.
Change database to PostgreSQL

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).
make NTP pool configurable

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.
Set individual variables for each cert

Allow a different cert for each host, defaulting to the same wildcard
cert.
Correct variable names

The variable names for the mail ssl certificates were transposed. Match
the playbook to the default.yml variables.
Fix variable use

variables are wrapped in double braces {{ }}
Wrap variable use in quotes

YAML mistakes the {{ }} for an array, in order to substitute correctly,
you have to wrap the variables in quotes.
Change 10-ssl.conf to a J2 template

In order to set the appropriate SSL cert, the 10-ssl.conf file must be a
template.
Set certificate files

For each host use the appropriate certificate file.