Issue #2329787 by cilefen, tuutti | davidhernandez: Move RDF classes from preprocess to templates.
Issue #999338 by lauriii, joelpittet, Sir-Arturio, mgifford, mlncn, alarcombe, sun | Eric_A: Fixed theme_image() alt attribute cannot be passed in $variables['attributes'] .
Issue #2332295 followup by klausi: Fixed Unicode requirements check not working with PHP 5.6.