Add $custom_fragment_params to apache::vhost
The custom fragment templates run in the scope of the apache::vhost
type. In Puppet 3.x dynamic variable lookups are no longer supported.
This will prevent extra data from being passed to the custom fragments.

This commit adds the $custom_fragment_params parameter to the apache::vhost
type to allow users to pass data through to apache::vhost for use by the templates.
This methods expects users to pass the information through as a hash.