Theme system improvements

Here are theme system improvements or CSS/XHTML items in the queue that could use the eyes of designer/themer-types.

• Allow customizing themes from the UI
• Add $classes to hook templates
• Refactor page (and node) rendering
• Allow Inline CSS in drupal_add_css
• Allow external CSS in drupal_add_css
• Allof CSS files to be altered (hook_css_alter)
• Add numeric weight to drupal_add_css

See also: All theme-related patches

Fixed

• Allow preprocess functions without a corresponding .tpl.php file
• Revamp drupal_add_css()