Add migrate support

Here is a patch that adds support for the profile2_privacy field.

It is a basic field so usage is just like any other field.

For example:

<?php
    // Profile2_privacy field.
    // The field expects a pplid.
    $this->addFieldMapping('field_profile_visibility', 'profile_visibility')
      ->defaultValue(2)
      ->description(t("The user's profile visibility."));
?>

Damn it. Here is the patch.

I've used it on one migration and it worked aok.