I wrote a quick plugin that does this. Copy and paste the following into a file called stml_beheader.php in your plugins folder and activate.
//////////////////////////////////////////
<?php
/*
Plugin Name: STML Beheader
Description: Removes unneccesary stuff from wp_head
Author: James Bridle
Version: 1.0
Author URI: http://shorttermmemoryloss.com
*/
remove_action( 'wp_head', 'feed_links_extra', 3 );
?>
//////////////////////////////////////////
You can remove other unwanted stuff as well by adding lines like:
remove_action('wp_head', 'wlwmanifest_link');
remove_action('wp_head', 'rsd_link');
Hope that works for you.