Git commits in Moodle 2.1.6 by Tony Levi

commit 3e86502dba186ef880980035c8b17707538147e7
Author: Tony Levi <tony.levi@netspot.com.au>
Date:   Tue, 10 Apr 2012 11:45:39 +0800
Tag:    v2.1.6

MDL-32379: Fix memory leak in session_set_user