Moved the extended_status scoreboard update from ap_process_http_connection

to the EOR bucket destructor.  Also, added some defensive code and comments
regarding r->pool lifetime to ap_process_http_connection.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@329664 13f79535-47bb-0310-9956-ffa450edef68