The Strict Transport Security plugin implements the Strict Transport Security header, improving the security of HTTPS only sites.
See http://lists.w3.org/Archives/Public/www-archive/2009Sep/att-0051/draft-hodges-strict-transport-sec-05.plain.html for the specification.

Installation
============
add "addPlugin('strictTransportSecurity');"
to the bottom of your config.php

The plugin will not do anything unless:
$config['site']['ssl'] is set to something other than 'never'
$config['site']['path'] is either not set, empty, or '/'

Settings
========
max_age (15552000): sets how long to remember the forced HTTPS (seconds) (15552000 seconds is 180 days)
includeSubDomains (false): if set, then STS will apply to all the sub-domains too.

Example
=======
addPlugin('strictTransportSecurity');