function custom_login_error_message() {
    return 'Oops! Something went wrong here.';
}
add_filter('login_errors', 'custom_login_error_message');

function new_excerpt_more($more) {
    global $post;
    return '… <a href="'. get_permalink($post->ID) . '">' . 'Read More &raquo;' . '</a>';
}
add_filter('excerpt_more', 'new_excerpt_more');

add_filter( 'avatar_defaults', 'new_default_avatar' );
function new_default_avatar ( $avatar_defaults ) {
    $myavatar = 'URL_TO_NEW_DEFAULT_AVATAR';
    $avatar_defaults[$myavatar] = "Default Avatar";
    return $avatar_defaults;
}

function custom_admin_footer() {
    echo 'Add your custom message here.';
}
add_filter('admin_footer_text', 'custom_admin_footer');

function my_custom_login_url() {
    return home_url();
}
add_filter('login_headerurl', 'my_custom_login_url');