Heartbeat: improve setting the errorstate, add ajaxurl to the settings object when loading on the front-end, some code cleanup, see #23216

git-svn-id: http://core.svn.wordpress.org/trunk@23882 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/general-template.php

@@ -2333,6 +2333,9 @@ function __checked_selected_helper( $helper, $current, $echo, $type ) {
  * @return array $settings
  */
 function wp_heartbeat_settings( $settings ) {
+	if ( ! is_admin() )
+		$settings['ajaxurl'] = admin_url( 'admin-ajax.php', 'relative' );
+
 	if ( is_user_logged_in() )
 		$settings['nonce'] = wp_create_nonce( 'heartbeat-nonce' );