Add 'plural' <body> class so that theme authors can style non-singular pages easier.
Add the hybrid_post_format_link() and hybrid_get_post_format_link() functions for outputting/getting the post format archive link.
Introduce hybrid_single_*_title() functions for handling many archive titles that WordPress core doesn't handle. These will be useful throughout the framework and in themes because they contain information that is often used in various places. Plus, this will allow us to standardize on date/time strings and keep them consistent for translators.
Add hybrid_search_title() and hybrid_404_title() functions.
Introduce functions for outputting common data to the `<head>` area of a site.  This also deprecates the hybrid_document_title() function in favor of a filter on wp_title.