Add overriding to debug emails, when it lands in core.

I've also added a note to the readme about it.

automatic-updater.php

@@ -94,8 +94,10 @@ function __construct() {
 		else
 			add_filter( 'auto_core_update_send_email', '__return_true', 1 );
 
-		if ( ! empty( $this->options['override-email'] ) )
+		if ( ! empty( $this->options['override-email'] ) ) {
 			add_filter( 'auto_core_update_email', array( $this, 'override_update_email' ), 1, 1 );
+			add_filter( 'auto_update_debug_email', array( $this, 'override_update_email' ), 1, 1 );
+		}
 
 		if ( $this->options['debug'] )
 			add_filter( 'automatic_updates_send_debug_email', '__return_true', 1 );

readme.txt

@@ -39,6 +39,12 @@ There are some Actions and Filters provided, check the [Documentation](http://pe
 1. Checkout the current development version from http://plugins.svn.wordpress.org/automatic-updater/trunk/
 1. Subscribe to the [RSS feed](http://plugins.trac.wordpress.org/log/automatic-updater?limit=100&mode=stop_on_copy&format=rss) to be notified of changes
 
+== Frequently Asked Questions ==
+
+= Why is the debug email going to the admin email address, instead of the override email address? =
+
+The debug email doesn't provide a filter to allow changing the email address it's being sent to. This will hopefully change in a future release of WordPress, you can follow progress in [this ticket](http://core.trac.wordpress.org/ticket/25756).
+
 == Changelog ==
 
 = 1.0 =
@@ -181,3 +187,8 @@ With the release of WordPress 3.7, Automatic Updater is now know as Advanced Aut
 
 = 0.1 =
 * Initial release
+
+== Upgrade Notice ==
+
+= 1.0 =
+With the release of WordPress 3.7, Automatic Updater is now know as Advanced Automatic Updates!