i18n functions and styles.
Restore customize.php because it's needed for loading customizer classes.
Add the Hybrid_Customize_Control_Background_Image class which extends the theme customizer background image control.  The purpose of this class is to allow theme authors to add multiple default backgrounds for users to choose from.
Remove filter on 'extra_theme_headers'.
Add the hybrid_get_menu() function for loading menu templates.
Add the hybrid_get_sidebar() function.
Allow for comment templates in the "/comment" sub-directory.
Beef up the hybrid_get_content_template() function. This adds smarter support for attachments and allows for content templates in the "/content" sub-folder.
hybrid_body_class() cleanup.
Deprecated hybrid_body_attributes(), hybrid_post_attributes(), and hybrid_comment_attributes() in favor of the newer hybrid_attr().