to mitigate POODLE vulnerability

Postfix: Disable SSLv2 and SSLv3 for 'mandatory SSL' mode connections to completely mitigate the POODLE issue.

http://ahbl.org/content/changes-ahbl

Fixes #232

Fixes issue #8. Adds new variable mail_header_privacy, on by default.
Installs postfix-pcre unconditionally, and then copies the pcre file
over and adds the header check to main.cf based on the variable value.
“this header replacement works great, but it logs that the replacement
has been done, which means that you are storing this information,
unless you are anonymizing your logs”

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).

These are the changes necessary to enable Roundcube's manage sieve plugin to mange server-side sieve filters.

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

Added friendly_networks variable to denote whitelisted networks

(such as root's cron errors)

Fix CAcert usage in postfix and dovecot

Fix Postfix configuration file to link to correct SSL certificate locations