Git merges in Moodle 1.9.15 by Aparup Banerjee

commit 9d7e30f9b8c6bceb7f24ea1bedcbf008e1064ad1
Author: Aparup Banerjee <aparup@moodle.com>
Date:   Wed, 09 Nov 2011 13:37:41 +0800
Tag:    v1.9.15

Merge branch 'MDL-29977-mnet-masquerade_19_STABLE' of git://github.com/mudrd8mz/moodle into MOODLE_19_STABLE