Ch 768: Page variations unibar changes

Allow personalize elements settings to be generated in their own function.
Add a few other settings needed by unibar changes.
Because this unsetting of the option sets has been moved in here, they're not getting unset in hook_page_build above, and so personalize_element_with_option_set() is getting called for all option sets of type 'elements' on every page. I'm getting js errors on all admin pages because the js settings are there for these elements option sets but Drupal.settings.personalize_elements.elements is not there.