- Added $classes and $classes_array to all templates, not just Zen's templates.
- Renamed page.tpl's $body_classes and $body_classes_array to $classes and $classes_array
- #564068: Views classes are missing from $classes variable

#317417 by JohnAlbin and quicksketch: Fix off-line maintenance page since drupal_get_path('theme', 'zen') won't work