Function: wp_nav_menu() callback from the main navigation in header.php

Function: Get our wp_nav_menu() fallback, bp_dtheme_main_nav(), to show a home link.

Function: Applies BuddyPress customisations to the post comment form.

Function: Adds the user’s avatar before the comment form box.

Function: Closes tags opened in bp_dtheme_before_comment_form().

Function: Adds a hidden “redirect_to” input field to the sidebar login form.

Function: Display navigation to next/previous pages when applicable

Function: Register widgetised areas, including one sidebar and four widget-ready columns in the footer.

Function: Sets up theme defaults and registers support for various WordPress and BuddyPress features.